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The Asiatic Lion is a lion population of the subspecies Panthera leo leo. Until the 19th century, it occurred in Saudi Arabia, eastern Turkey, Iran, Mesopotamia, and from east of the Indus River in Pakistan to the Bengal region and the Narmada River in Central India. Since the turn of the 20th century, its range has been restricted to Gir National Park and the surrounding areas in the Indian state of Gujarat. The first scientific description of the Asiatic lion was published in 1826 by the Austrian zoologist Johann N. Meyer, who named it Felis leo persicus.

The population has steadily increased since 2010. In 2015, the 14th Asiatic Lion Census was conducted over an area of about 20,000 km² (7,700 sq mi); the lion population was estimated at 523 individuals, and in 2017 at 650 individuals.

Taxonomy

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Felis leo persicus was the scientific name proposed by Johann N. Meyer in 1826 who described an Asiatic lion skin from Persia.^[2] In the 19th century, several zoologists described lion zoological specimen from other parts of Asia that used to be considered synonyms of P. l. persica:^[3]

• Felis leo bengalensis proposed by Edward Turner Bennett in 1829 was a lion kept in the menagerie of the Tower of London. Bennett’s essay contains a drawing titled ‘Bengal lion’.^[4]
• Felis leo goojratensis proposed by Walter Smee in 1833 was based on two skins of maneless lions from Gujarat that Smee exhibited in a meeting of the Zoological Society of London.^[5]
• Leo asiaticus proposed by Sir William Jardine, 7th Baronet in 1834 was a lion from India.^[6]
• Felis leo indicus proposed by Henri Marie Ducrotay de Blainville in 1843 was based on an Asiatic lion skull.^[7]

In 2017, the Asiatic lion was subsumed to P. l. leo due to close morphological and molecular genetic similarities with Barbary lion specimens.^[8][9] However, several scientists continue using P. l. persica for the Asiatic lion.^{[10][11][12][13][14][15]} A standardised haplogroup phylogeny supports that the Asiatic lion is not a distinct subspecies, and that it represents a haplogroup of the northern P. l. leo.^[16]

Evolution

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Main article: Lion § Evolution and phylogeny

Lions first left Africa at least 700,000 years ago, giving rise to the Eurasian Panthera fossilis which later evolved into Panthera spelaea (commonly known as the cave lion), which became extinct around 14,000 years ago. Genetic analysis of P. spelaea indicates that it represented a distinct species from the modern lion that diverged from them around 500,000 years ago and unrelated to modern Asian lions.^[17] Pleistocene fossils assigned as belonging or probably belonging to the modern lion have been reported from several sites in the Middle East, such as Shishan Marsh in the Azraq Basin, Jordan, dating to around 250,000 years ago,^[18] and Wezmeh Cave in the Zagros Mountains of western Iran, dating to around 70–10,000 years ago,^[19] with other reports from Pleistocene deposits in Nadaouiyeh Ain Askar and Douara Cave, Syria.^[18] In 1976, fossil lion remains were reported from Pleistocene deposits in West Bengal.^[20] A fossil carnassial excavated from Batadomba Cave indicates that lions inhabited Sri Lanka during the Late Pleistocene. This population may have become extinct around 39,000 years ago, before the arrival of humans in Sri Lanka.^[21]

Phylogeography

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Results of a phylogeographic analysis based on mtDNA sequences of lions from across the global range, including now extinct populations like Barbary lions, indicates that sub-Saharan African lions are phylogenetically basal to all modern lions. These findings support an African origin of modern lion evolution with a probable centre in East and Southern Africa. It is likely that lions migrated from there to West Africa, eastern North Africa and via the periphery of the Arabian Peninsula into Turkey, southern Europe and northern India during the last 20,000 years. The Sahara, Congolian rainforests and the Great Rift Valley are natural barriers to lion dispersal.^[22]

Genetic markers of 357 samples from captive and wild lions from Africa and India were examined. Results indicate four lineages of lion populations: one in Central and North Africa to Asia, one in Kenya, one in Southern Africa, and one in Southern and East Africa; the first wave of lion expansion probably occurred about 118,000 years ago from East Africa into West Asia, and the second wave in the late Pleistocene or early Holocene periods from Southern Africa towards East Africa.^[23] The Asiatic lion is genetically closer to North and West African lions than to the group comprising East and Southern African lions. The two groups probably diverged about 186,000–128,000 years ago. It is thought that the Asiatic lion remained connected to North and Central African lions until gene flow was interrupted due to extinction of lions in Western Eurasia and the Middle East during the Holocene.^[24][25]

Asiatic lions are less genetically diverse than African lions, which may be the result of a founder effect in the recent history of the remnant population in the Gir Forest.^[26]

Characteristics

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The Asiatic lion’s fur ranges in colour from ruddy-tawny, heavily speckled with black, to sandy or buffish grey, sometimes with a silvery sheen in certain lighting. Males have only moderate mane growth at the top of the head, so that their ears are always visible. The mane is scanty on the cheeks and throat, where it is only 10 cm (4 in) long. About half of Asiatic lions’ skulls from the Gir forest have divided infraorbital foramina, whereas African lions have only one foramen on either side. The sagittal crest is more strongly developed, and the post-orbital area is shorter than in African lions. Skull length in adult males ranges from 330–340 mm (13–13+¹⁄₂ in), and in females, from 292–302 mm (11+¹⁄₂–11+⁷⁄₈ in). It differs from the African lion by a larger tail tuft and less inflated auditory bullae.^[3] The most striking morphological character of the Asiatic lion is a longitudinal fold of skin running along its belly.^[27]

Males have a shoulder height of up to 107–120 cm (42–47 in), and females of 80–107 cm (31+¹⁄₂–42 in).^[28] Two lions in Gir Forest measured 1.98 m (6 ft 6 in) from head to body with a 0.79–0.89 m (31–35 in) long tail of and total lengths of 2.82–2.87 m (9 ft 3 in – 9 ft 5 in). The Gir lion is similar in size to the Central African lion,^[3] and smaller than large African lions.^[29] An adult male Asiatic lion weighs 160.1 kg (353 lb) on average with the limit being 190 kg (420 lb); a wild female weighs 100 to 130 kg (220 to 285 lb).^[30][31][1]

Manes

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Colour and development of manes in male lions varies between regions, among populations and with age of lions.^[32] In general, the Asiatic lion differs from the African lion by a less developed mane.^[3] The manes of most lions in ancient Greece and Asia Minor were also less developed and did not extend to below the belly, sides or ulnas. Lions with such smaller manes were also known in the Syrian region, Arabian Peninsula and Egypt.^[33][34]

Exceptionally sized lions

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The confirmed record total length of a male Asiatic lion is 2.92 m (9 ft 7 in), including the tail.^[35] Emperor Jahangir allegedly speared a lion in the 1620s that measured 3.10 m (10 ft 2 in) and weighed 306 kg (675 lb).^[36] In 1841, English traveller Austen Henry Layard accompanied hunters in Khuzestan, Iran, and sighted a lion which “had done much damage in the plain of Ram Hormuz,” before one of his companions killed it. He described it as being “unusually large and of very dark brown colour”, with some parts of its body being almost black.^[37] In 1935, a British admiral claimed to have sighted a maneless lion near Quetta in Pakistan. He wrote “It was a large lion, very stocky, light tawny in colour, and I may say that no one of us three had the slightest doubt of what we had seen until, on our arrival at Quetta, many officers expressed doubts as to its identity, or to the possibility of there being a lion in the district.”^[38]

Distribution and habitat

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In Saurashtra‘s Gir forest, an area of 1,412.1 km² (545.2 sq mi) was declared as a sanctuary for Asiatic lion conservation in 1965. This sanctuary and the surrounding areas are the only habitats supporting the Asiatic lion.^[39] After 1965, a national park was established covering an area of 258.71 km² (99.89 sq mi) where human activity is not allowed. In the surrounding sanctuary only Maldharis have the right to take their livestock for grazing.^[40]

Lions inhabit remnant forest habitats in the two hill systems of Gir and Girnar that comprise Gujarat’s largest tracts of tropical and subtropical dry broadleaf forests, thorny forest and savanna, and provide valuable habitat for a diverse flora and fauna. Five protected areas currently exist to protect the Asiatic lion: Gir Sanctuary, Gir National Park, Pania Sanctuary, Mitiyala Sanctuary, and Girnar Sanctuary. The first three protected areas form the Gir Conservation Area, a 1,452 km² (561 sq mi) large forest block that represents the core habitat of the lion population. The other two sanctuaries Mitiyala and Girnar protect satellite areas within dispersal distance of the Gir Conservation Area. An additional sanctuary is being established in the nearby Barda Wildlife Sanctuary to serve as an alternative home for lions.^[39] The drier eastern part is vegetated with acacia thorn savanna and receives about 650 mm (26 in) annual rainfall; rainfall in the west is higher at about 1,000 mm (39 in) per year.^[30]

The lion population recovered from the brink of extinction to 411 individuals by 2010. In that year, approximately 105 lions lived outside the Gir forest, representing a quarter of the entire lion population. Dispersing sub-adults established new territories outside their natal prides, and as a result the satellite lion population has been increasing since 1995.^[39] By 2015, the total population had grown to an estimated 523 individuals, inhabiting an area of 7,000 km² (2,700 sq mi) in the Saurashtra region., comprising 109 adult males, 201 adult females and 213 cubs.^[41][10][42] The Asiatic Lion Census conducted in 2017 revealed about 650 individuals.^[43]

By 2020, at least six satellite populations had spread to eight districts in Gujarat and live in human-dominated areas outside the protected area network.^[44] 104 lived near the coastline. Lions living along the coast, as well as those between the coastline and the Gir forest, have larger individual ranges.^[45] By the time of the census, approximately 300-325 lions lived within the Gir preserve itself. The remainder of the population was instead spread across the adjoining Amreli, Bhavnagar, and Gir Somnath Districts, with populations recorded in the Girnar, Mitiyala, and Pania Wildlife Sanctuaries in addition to areas outside protected zones.^[43][46] In 2024 and 2025, lions began swimming to Diu Island, separated from the mainland of Gujarat by a narrow channel. These individuals were relocated to Gujarat on request of the Diu administration over concerns of disruption to human life, although conservationists protested the removal as unnecessary.^[46]

Former range

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During the Holocene, from around 6,500 years ago and possibly as early as 8,000 years ago, modern lions colonised Southeast Europe (including modern Bulgaria and Greece in the Balkans), as well as parts of Central Europe like Hungary and Ukraine in Eastern Europe. Analysis of remains of these European lions suggests that they do not differ from those of modern Asiatic lions, and they should be assigned to this population.^[47] Historical records suggest that lions became extinct in Europe during Classical antiquity,^[48] though it has been suggested that they may have survived as late as the Middle Ages in Ukraine.^[47]

Men with a chained lion in Iran, c. 1880.^[49] Photograph by Antoin Sevruguin exhibited in the National Museum of Ethnology (Netherlands)

The Lion Hunt of Ashurbanipal, a sequence of Assyrian palace reliefs, Nineveh, Mesopotamia, 7th century BC

The Asiatic lion used to occur in Arabia, the Levant, Mesopotamia and Baluchistan.^[3] In South Caucasia, it was known since the Holocene and became extinct in the 10th century. Until the middle of the 19th century, it survived in regions adjoining Mesopotamia and Syria, and was still sighted in the upper reaches of the Euphrates River in the early 1870s.^[33][50] By the late 19th century, it had become extinct in Saudi Arabia and Turkey.^[51][52] The last known lion in Iraq was killed on the lower Tigris in 1918.^[53]

Historical records in Iran indicate that it ranged from the Khuzestan Plain to Fars province at elevations below 2,000 m (6,600 ft) in steppe vegetation and pistachio–almond woodlands.^[54] It was widespread in the country, but in the 1870s, it was sighted only on the western slopes of the Zagros Mountains, and in the forest regions south of Shiraz.^[33] It served as the national emblem and appeared on the country’s flag. Some of the country’s last lions were sighted in 1941 between Shiraz and Jahrom in Fars province, and in 1942, a lion was spotted about 65 km (40 mi) northwest of Dezful.^[55] In 1944, the corpse of a lioness was found on the banks of the Karun River in Iran’s Khuzestan province.^[56][57]

In India, the Asiatic lion occurred in Sind, Bahawalpur, Punjab, Gujarat, Rajasthan, Haryana, Bihar and eastward as far as Palamau and Rewa, Madhya Pradesh in the early 19th century.^[58][37] It once ranged to Bangladesh in the east and up to Narmada River in the south.^[37] Because of the lion’s restricted distribution in India, Reginald Innes Pocock assumed that it arrived from Europe, entering southwestern Asia through Balochistan only recently, before humans started limiting its dispersal in the country. The advent and increasing availability of firearms led to its local extirpation over large areas.^[3] Heavy hunting by British colonial officers and Indian rulers caused a steady and marked decline of lion numbers in the country.^[40] Lions were exterminated in Palamau by 1814, in Baroda State, Hariana and Ahmedabad district in the 1830s, in Kot Diji and Damoh district in the 1840s. During the Indian Rebellion of 1857, a British officer shot 300 lions. The last lions of Gwalior and Rewah were shot in the 1860s. One lion was killed near Allahabad in 1866.^[58] The last lion of Mount Abu in Rajasthan was spotted in 1872.^[59] By the late 1870s, lions were extinct in Rajasthan.^[37] By 1880, no lion survived in Guna, Deesa and Palanpur districts, and only about a dozen lions were left in Junagadh district. By the turn of the century, the Gir Forest held the only Asiatic lion population in India, which was protected by the Nawab of Junagarh in his private hunting grounds.^[3][37]

Ecology and behaviour

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A male lion scent marking his territory in Gir Forest

Female and male lion

Young male

Male Asiatic lions are solitary, or associate with up to three males, forming a loose pride. Pairs of males rest, hunt and feed together, and display marking behaviour at the same sites. Females associate with up to twelve other females, forming a stronger pride together with their cubs. They share large carcasses among each other, but seldom with males. Female and male lions usually associate only for a few days when mating, but rarely live and feed together.^[60][61]

Results of a radio telemetry study indicate that annual home ranges of male lions vary from 144 to 230 km² (56 to 89 sq mi) in dry and wet seasons. Home ranges of females are smaller, varying between 67 and 85 km² (26 and 33 sq mi).^[62] During hot and dry seasons, they favour densely vegetated and shady riverine habitats, where prey species also congregate.^[63][64]

Coalitions of males defend home ranges containing one or more female prides.^[65] Together, they hold a territory for a longer time than single lions. Males in coalitions of three to four individuals exhibit a pronounced hierarchy with one male dominating the others.^[66]

The lions in Gir National Park are active at twilight and by night, showing a high temporal overlap with sambar (Rusa unicolor), wild boar (Sus scrofa) and nilgai (Boselaphus tragocamelus).^[14]

Feeding ecology

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In general, lions prefer large prey species within a weight range of 190 to 550 kg (420 to 1,210 lb), irrespective of their availability.^[67] Domestic cattle have historically been a major component of the Asiatic lions’ diet in the Gir Forest.^[3] Inside Gir Forest National Park, lions predominantly kill chital (Axis axis), sambar deer, nilgai, cattle (Bos taurus), domestic water buffalo (Bubalus bubalis), and less frequently wild boar.^[62] They most commonly kill chital, which weighs only around 50 kg (110 lb).^[65] They prey on sambar deer when the latter descend from the hills during summer. Outside the protected area where wild prey species do not occur, lions prey on water buffalo and cattle, and rarely on dromedary (Camelus dromedarius). They generally kill most prey less than 100 m (330 ft) away from water bodies, charge prey from close range and drag carcasses into dense cover.^[62] They regularly visit specific sites within the protected area to scavenge on dead livestock dumped by Maldhari livestock herders.^[68] During dry, hot months, they also prey on mugger crocodiles (Crocodylus palustris) on the banks of Kamleshwar Dam.^[57]: 148

In 1974, the Forest Department estimated the wild ungulate population at 9,650 individuals. In the following decades, the wild ungulate population has grown consistently to 31,490 in 1990 and 64,850 in 2010, including 52,490 chital, 4,440 wild boar, 4,000 sambar, 2,890 nilgai, 740 chinkara (Gazella bennetti), and 290 four-horned antelope (Tetracerus quadricornis). In contrast, populations of domestic buffalo and cattle declined following resettlement, largely due to direct removal of resident livestock from the Gir Conservation Area. The population of 24,250 domestic livestock in the 1970s declined to 12,500 by the mid-1980s, but increased to 23,440 animals in 2010. Following changes in both predator and prey communities, Asiatic lions shifted their predation patterns. Today, very few livestock kills occur within the sanctuary, and instead most occur in peripheral villages. Depredation records indicate that in and around the Gir Forest, lions killed on average 2,023 livestock annually between 2005 and 2009, and an additional 696 individuals in satellite areas.^[39]

Dominant males consume about 47% more from kills than their coalition partners. Aggression between partners increases when coalitions are large, but kills are small.^[66]

Reproduction

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Lions mating in Gir Forest

A pride of adult lions and their cubsAsiatic lions mating

Asiatic lions mate foremost between October and November.^[69] Mating lasts three to six days. During these days, they usually do not hunt, but only drink water. Gestation lasts about 110 days. Litters comprise one to four cubs.^[70] The average interval between births is 24 months, unless cubs die due to infanticide by adult males or because of diseases and injuries. Cubs become independent at the age of about two years. Subadult males leave their natal pride latest at the age of three years and become nomads until they establish their own territory.^[61] Dominant males mate more frequently than their coalition partners. During a study carried out between December 2012 and December 2016, three females were observed switching mating partners in favour of the dominant male.^[66] Monitoring of more than 70 mating events showed that females mated with males of several rivaling prides that shared their home ranges, and that these males were tolerant toward the same cubs. Only new males that entered the female territories killed unfamiliar cubs. Young females mated foremost with males within their home ranges. Older females selected males at the periphery of their home ranges.^[71]

Threats

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The Asiatic lion currently exists as a single subpopulation, and is thus vulnerable to extinction from unpredictable events, such as an epidemic or large forest fire. There are indications of poaching incidents in recent years, as well as reports that organized poacher gangs have switched attention from local Bengal tigers to the Gujarat lions. There have also been a number of drowning incidents, after lions fell into wells.^[1]

Prior to the resettlement of Maldharis, the Gir forest was heavily degraded and used by livestock, which competed with and restricted the population sizes of native ungulates. Various studies reveal tremendous habitat recovery and increases in wild ungulate populations following the resettlement of Maldharis since the 1970s.^[39]

Nearly 25 lions in the vicinity of Gir Forest were found dead in October 2018. Four of them had died because of canine distemper virus, the same virus that had also killed several lions in the Serengeti.^[72][73]

Conflicts with humans

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Since the mid-1990s, the Asiatic lion population has increased to an extent that by 2015, about a third resided outside the protected area. Hence, conflict between local residents and wildlife also increased. Local people protect their crops from nilgai, wild boar, and other herbivores by using electrical fences that are powered with high voltage. Some consider the presence of predators a benefit, as they keep the herbivore population in check. But some also fear the lions, and killed several in retaliation for attacks on livestock.^[74]

In July 2012, a lion dragged a man from the veranda of his house and killed him about 50–60 km (31–37 miles) from Gir Forest National Park. This was the second attack by a lion in this area, six months after a 25-year-old man was attacked and killed in Dhodadar.^[75]

Conservation

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Panthera leo persica was included on CITES Appendix I, and is fully protected in India,^[38] where it is considered endangered.^[76]

Reintroduction

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India

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Main article: Asiatic Lion Reintroduction Project

In the 1950s, biologists advised the Indian government to re-establish at least one wild population in the Asiatic lion’s former range to ensure the population’s reproductive health and to prevent it from being affected by an outbreak of an epidemic. In 1956, the Indian Board for Wildlife accepted a proposal by the Government of Uttar Pradesh to establish a new sanctuary for the envisaged reintroduction, Chandra Prabha Wildlife Sanctuary, covering 96 km² (37 sq mi) in eastern Uttar Pradesh, where climate, terrain and vegetation is similar to the conditions in the Gir Forest. In 1957, one male and two female wild-caught Asiatic lions were set free in the sanctuary. This population comprised 11 animals in 1965, which all disappeared thereafter.^[77]

The Asiatic Lion Reintroduction Project to find an alternative habitat for reintroducing Asiatic lions was pursued in the early 1990s. Biologists from the Wildlife Institute of India assessed several potential translocation sites for their suitability regarding existing prey population and habitat conditions. The Palpur-Kuno Wildlife Sanctuary in northern Madhya Pradesh was ranked as the most promising location, followed by Sita Mata Wildlife Sanctuary and Darrah National Park.^[78] Until 2000, 1,100 families from 16 villages had been resettled from the Palpur-Kuno Wildlife Sanctuary, and another 500 families from eight villages were expected to be resettled. With this resettlement scheme the protected area was expanded by 345 km² (133 sq mi).^[77][79]

Gujarat state officials resisted the relocation, since it would make the Gir Sanctuary lose its status as the world’s only home of the Asiatic lion. Gujarat raised a number of objections to the proposal, and thus the matter went before the Indian Supreme Court. In April 2013, the Indian Supreme Court ordered the Gujarat state to send some of their Gir lions to Madhya Pradesh to establish a second population there.^[80] The Gujarat state government has resisted relocation of lions to other states.^[81]

Iran

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See also: Iran’s Project Lion

In 1977, Iran attempted to restore its lion population by transporting Gir lions to Arzhan National Park, but the project met resistance from the local population, and thus it was not implemented.^[50][55] However, this did not stop Iran from seeking to bring back the lion.^[82][83] In February 2019, Tehran Zoological Garden obtained a male Asiatic lion from Bristol Zoo in the United Kingdom,^[84] followed in June by a female from Dublin Zoo. There are hopes for them to successfully reproduce.^[85]

In captivity

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Asiatic lion in Planckendael, Belgium

Asiatic lion in Tierpark Berlin

Until the late 1990s, captive Asiatic lions in Indian zoos were haphazardly interbred with African lions confiscated from circuses, leading to genetic pollution in the captive Asiatic lion stock. Once discovered, this led to the complete shutdown of the European and American endangered species breeding programs for Asiatic lions, as its founder animals were captive-bred Asiatic lions originally imported from India and were ascertained to be intraspecific hybrids of African and Asian lions. In North American zoos, several Indian-African lion crosses were inadvertently bred, and researchers noted that “the fecundity, reproductive success, and spermatozoal development improved dramatically.”^[86][87]

DNA fingerprinting studies of Asiatic lions have helped in identifying individuals with high genetic variability, which can be used for conservation breeding programs.^[88]

In 2006, the Central Zoo Authority of India stopped breeding Indian-African cross lions stating that “hybrid lions have no conservation value and it is not worth to spend resources on them”.^[86][89] Now only pure native Asiatic lions are bred in India.

In 1972 the Sakkarbaug Zoo sold a pair of young pure-stock lions to the Fauna Preservation Society; which decided they would be accommodated at the Jersey Wildlife Trust where it was hoped to begin a captive breeding programme.^[90]

The Asiatic lion International Studbook was initiated in 1977, followed in 1983 by the North American Species Survival Plan (SSP).^[91] The North American population of captive Asiatic lions was composed of descendants of five founder lions, three of which were pure Asian and two were African or African-Asian hybrids. The lions kept in the framework of the SSP consisted of animals with high inbreeding coefficients.^[27]

In the early 1990s, three European zoos imported pure Asiatic lions from India: London Zoo obtained two pairs; the Zürich Zoologischer Garten one pair; and the Korkeasaari Zoo in Helsinki one male and two females. In 1994, the European Endangered Species Programme (EEP) for Asiatic lions was initiated. The European Association of Zoos and Aquaria (EAZA) published the first European Studbook in 1999. By 2005, there were 80 Asiatic lions kept in the EEP – the only captive population outside of India.^[91] As of 2009, more than 100 Asiatic lions were kept within the EEP. The SSP had not resumed; pure-bred Asiatic lions are needed to form a new founder population for breeding in American zoos.^[92]

In culture

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The original sandstone sculpted Lion Capital of Ashoka preserved at Sarnath Museum, which was originally erected around 250 BC atop an Ashoka Pillar at Sarnath

Lion depicted in a 15th century Persian manuscript kept at the Topkapi Palace Museum

A painting showing a lion hunt in India, ca. 1810

Further information: Lion (heraldry) and Cultural depictions of lions

South and East Asia

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See also: Bharat Mata and Kangla Sha

Neolithic cave paintings of lions were found in Bhimbetka rock shelters in central India, which are at least 30,000 years old.^[93]

The Sanskrit word for ‘lion’ is ‘सिंह’ siṃhaḥ, which is also a name of Shiva and signifies the Leo of the Zodiac.^[94] The Sanskrit name of Sri Lanka is Sinhala meaning ‘Abode of Lions’.^[95] Singapore derives its name from the Malay words singa ‘lion’ and pura ‘city’, which in turn is from the Sanskrit ‘सिंह’ siṃhaḥ and पुर pur, latter also meaning ‘fortified town’.^[94][96]

In Hindu mythology, the half man half lion avatar Narasimha is the fourth incarnation of Vishnu.^[97] Simhamukha is a lion-faced protector and dakini in Tibetan Buddhism.^[98]

In the 18th book of the Mahabharata, Bharata deprives lions of their prowess.^[99] The lion plays a prominent role in The Fables of Pilpay that were translated into Persian, Greek and Hebrew languages between the 8th and 12th centuries.^[100] The lion is the symbol of Mahavira, the 24th and last Tirthankara in Jainism.^[101][102]

• The lion is the third animal of the Burmese zodiac and the sixth animal of the Sinhalese zodiac.^[103]
• The earliest known Chinese stone sculptures of lions date to the Han dynasty at the turn of the first millennium.^[104]
• The lion dance is a traditional dance in Chinese culture that is strongly associated with Buddhism and known since at least the Han dynasty.^[105]
• Cambodia has a native martial art called Bokator (Khmer: ល្បុក្កតោ, pounding a lion).^[106]

West Asia and Europe

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Lions are depicted on vases dating to about 2600 BCE that were excavated near Lake Urmia in Iran.^[107] The lion was an important symbol in Ancient Iraq and is depicted in a stone relief at Nineveh in the Mesopotamian Plain.^[108][109]

• The lion makes repeated appearances in the Bible, most notably as having fought Samson in the Book of Judges.^{[citation needed]}
• Having occurred in the Arab world, particularly the Arabian Peninsula,^[33] the Asiatic lion has significance in Arab and Islamic culture. For example, Surah al-Muddaththir of the Quran criticizes people who were averse to the Islamic Prophet Muhammad‘s teachings, such as that the rich have an obligation to donate wealth to the poor, comparing their attitude to itself, with the response of prey to a qaswarah (Arabic: قَسْوَرَة, meaning “lion”, “beast of prey”, or “hunter”).^[110] Other Arabic words for ‘lion’ include asad (Arabic: أَسَد) and sabaʿ (Arabic: سَبَع),^[111] and they can be used as names of places, or titles of people. An Arabic toponym for the Levantine City of Beersheba (Arabic: بِئر ٱلسَّبَع) can mean “Spring of the Lion.”^[112] Ali ibn Abi Talib and Hamzah ibn Abdul-Muttalib, who were loyal kinsmen of Muhammad, were given titles like Asad Allah (Arabic: أَسَد ٱلله, lit. ‘Lion of God‘).^[113]
• The lion of Babylon is a statue at the Ishtar Gate in Babylon^[50] The lion has an important association with the figure Gilgamesh, as demonstrated in his epic.^[114] The Iraqi national football team is nicknamed “Lions of Mesopotamia.”^[115]
• The symbol of the lion is closely tied to the Persian people. Achaemenid kings were known to carry the symbol of the lion on their thrones and garments. The name ‘Shir’ (also pronounced ‘Sher’) (Persian: شیر) is a part of the names of many places in Iran and Central Asia, like those of city of Shiraz and the Sherabad River, and had been adopted into other languages, like Hindi.^[3][33][50] The Shir-va-Khorshid (Persian: شیر و خورشید, “Lion and Sun“) is one of the most prominent symbols of Iran, dating back to the Safavid dynasty, and was used on the flag of Iran until 1979.^[116]
• The lion was an objective of hunting in the Caucasus, by both locals and foreigners. The locals were called ‘Shirvanshakhs‘.^[33]
• The Nemean lion of pre-literate Greek myth is associated with the Labours of Hercules.^[117]
• A Bronze Age statue of a lion from either Southern Italy or southern Spain from around 1000–1200 years BCE, the “Mari-Cha Lion”, was exhibited at the Louvre Abu Dhabi.

Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,000 species have been classified. They are easily identified by their geniculate (elbowed) antennae and the distinctive node-like structure that forms their slender waists.

Ants form colonies that range in size from a few dozen individuals often living in small natural cavities to highly organised colonies that may occupy large territories with sizeable nest that consist of millions of individuals or into the hundreds of millions in super colonies. Typical colonies consist of various castes of sterile, wingless females, most of which are workers (ergates), as well as soldiers (dinergates) and other specialised groups. Nearly all ant colonies also have some fertile males called “drones” and one or more fertile females called “queens” (gynes). The colonies are described as superorganisms because the ants appear to operate as a unified entity, collectively working together to support the colony.

Ants have colonised almost every landmass on Earth. The only places lacking indigenous ants are Antarctica and a few remote or inhospitable islands. Ants thrive in moist tropical ecosystems and may exceed the combined biomass of wild birds and mammals. Their success in so many environments has been attributed to their social organisation and their ability to modify habitats, tap resources, and defend themselves. Their long co-evolution with other species has led to mimetic, commensal, parasitic, and mutualistic relationships.

Ant societies have division of labour, communication between individuals, and an ability to solve complex problems. These parallels with human societies have long been an inspiration and subject of study. Many human cultures make use of ants in cuisine, medication, and rites. Some species are valued in their role as biological pest control agents. Their ability to exploit resources may bring ants into conflict with humans, however, as they can damage crops and invade buildings. Some species, such as the red imported fire ant (Solenopsis invicta) of South America, are regarded as invasive species in other parts of the world, establishing themselves in areas where they have been introduced accidentally.

Etymology

The word ant and the archaic word emmet^[3] are derived from ante, emete of Middle English, which come from ǣmette of Old English; these are all related to Low Saxon e(e)mt, empe and varieties (Old Saxon emeta) and to German Ameise (Old High German āmeiza). All of these words come from West Germanic *ǣmaitjōn, and the original meaning of the word was “the biter” (from Proto-Germanic *ai-, “off, away” + *mait- “cut”).^[4][5]

The family name Formicidae is derived from the Latin formīca (“ant”)^[6] from which the words in other Romance languages, such as the Portuguese formiga, Italian formica, Spanish hormiga, Romanian furnică, and French fourmi are derived.

The study of ants is called myrmecology, from Ancient Greek μύρμηξ mýrmēx (“ant”). It has been hypothesised that a Proto-Indo-European word *morwi- was the root for Sanskrit vamrah, Greek μύρμηξ mýrmēx, Latin formīca, Old Church Slavonic mraviji, Old Irish moirb, Old Norse maurr, Dutch mier, Swedish myra, Danish myre, Middle Dutch miere, and Crimean Gothic miera.^[7][8]

Taxonomy and evolution

The family Formicidae belongs to the order Hymenoptera, which also includes sawflies, bees, and wasps. Ants evolved from a lineage within the stinging wasps, and a 2013 study suggests that they are a sister group of the Apoidea.^[9] However, since Apoidea is a superfamily, ants must be upgraded to the same rank.^[10] A more detailed basic taxonomy was proposed in 2020. Three species of the extinct mid-Cretaceous genera Camelomecia and Camelosphecia were placed outside of the Formicidae, in a separate clade within the general superfamily Formicoidea, which, together with Apoidea, forms the higher-ranking group Formicapoidina.^[2] Fernández et al. (2021) suggest that the common ancestors of ants and apoids within the Formicapoidina probably existed as early as in the end of the Jurassic period, before divergence in the Cretaceous.^[10]

AculeataChrysidoideaVespidaeRhopalosomatidaePompilidaeMutillidaeTiphiidaeChyphotidaeScolioideaApoideaFormicidae

Phylogenetic position of the Formicidae as seen in Johnson et al. (2013)[9][10]

FormicidaeFormicoidMyrmicinaeEctatomminaeHeteroponerinaeFormicinaeDolichoderinaeAneuretinaePseudomyrmecinaeMyrmeciinaeDorylinae‡PoneroidPonerinaeAgroecomyrmecinaeParaponerinaeProceratiinaeAmblyoponinaeApomyrminaeLeptanillinaeMartialinae

A phylogeny of the extant ant subfamilies.[11][12][13]*Cerapachyinae is paraphyletic ‡ The previous dorylomorph subfamilies – Ecitoninae, Aenictinae, Aenictogitoninae, Cerapachyinae, Leptanilloidinae – were synonymized under Dorylinae by Brady et al. in 2014[14]

In 1966, E. O. Wilson and his colleagues identified the fossil remains of an ant (Sphecomyrma) that lived in the Cretaceous period. The specimen, trapped in amber dating back to around 92 million years ago, has features found in some wasps, but not found in modern ants.^[15] The oldest fossils of ants date to the mid-Cretaceous, around 100 million years ago, which belong to extinct stem-groups such as the Haidomyrmecinae, Sphecomyrminae and Zigrasimeciinae, with modern ant subfamilies appearing towards the end of the Cretaceous around 80–70 million years ago.^[16] Ants diversified extensively during the Angiosperm Terrestrial Revolution^[17] and assumed ecological dominance around 60 million years ago.^{[18][1][19][20]} Some groups, such as the Leptanillinae and Martialinae, are suggested to have diversified from early primitive ants that were likely to have been predators underneath the surface of the soil.^[13][21]

During the Cretaceous period, a few species of primitive ants ranged widely on the Laurasian supercontinent (the Northern Hemisphere). Their representation in the fossil record is poor, in comparison to the populations of other insects, representing only about 1% of fossil evidence of insects in the era. Ants became dominant after adaptive radiation at the beginning of the Paleogene period. By the Oligocene and Miocene, ants had come to represent 20–40% of all insects found in major fossil deposits. Of the species that lived in the Eocene epoch, around one in 10 genera survive to the present. Genera surviving today comprise 56% of the genera in Baltic amber fossils (early Oligocene), and 92% of the genera in Dominican amber fossils (apparently early Miocene).^[18][22]

Termites live in colonies and are sometimes called “white ants”, but termites are only distantly related to ants. They are the sub-order Isoptera, and together with cockroaches, they form the order Blattodea. Blattodeans are related to mantids, crickets, and other winged insects that do not undergo complete metamorphosis. Like ants, termites are eusocial, with sterile workers, but they differ greatly in the genetics of reproduction. The similarity of their social structure to that of ants is attributed to convergent evolution.^[23] Velvet ants look like large ants, but are wingless female wasps.^[24][25]

Distribution and diversity

Region	Number of species [26]
Neotropics	2,162
Nearctic	580
Europe	180
Africa	2,500
Asia	2,080
Melanesia	275
Australia	985
Polynesia	42

Ants have a cosmopolitan distribution. They are found on all continents except Antarctica, and only a few large islands, such as Greenland, Iceland, parts of Polynesia and the Hawaiian Islands lack native ant species.^[27][28] Ants occupy a wide range of ecological niches and exploit many different food resources as direct or indirect herbivores, predators and scavengers. Most ant species are omnivorous generalists, but a few are specialist feeders. There is considerable variation in ant abundance across habitats, peaking in the moist tropics to nearly six times that found in less suitable habitats.^[29] Their ecological dominance has been examined primarily using estimates of their biomass: myrmecologist E. O. Wilson had estimated in 2009 that at any one time the total number of ants was between one and ten quadrillion (short scale) (i.e., between 10¹⁵ and 10¹⁶) and using this estimate he had suggested that the total biomass of all the ants in the world was approximately equal to the total biomass of the entire human race.^[30] More careful estimates made in 2022 which take into account regional variations puts the global ant contribution at 12 megatons of dry carbon, which is about 20% of the total human contribution, but greater than that of the wild birds and mammals combined. This study also puts a conservative estimate of the ants at about 20 × 10¹⁵ (20 quadrillion).^[31][32][33]

Ants range in size from 0.75 to 52 millimetres (0.030–2.0 in),^[34][35] the largest species being the fossil Titanomyrma giganteum, the queen of which was 6 cm (2+¹⁄₂ in) long with a wingspan of 15 cm (6 in).^[36] Ants vary in colour; most ants are yellow to red or brown to black, but a few species are green and some tropical species have a metallic lustre. More than 13,800 species are currently known^[37] (with upper estimates of the potential existence of about 22,000; see the article List of ant genera), with the greatest diversity in the tropics. Taxonomic studies continue to resolve the classification and systematics of ants. Online databases of ant species, including AntWeb and the Hymenoptera Name Server, help to keep track of the known and newly described species.^[37] The relative ease with which ants may be sampled and studied in ecosystems has made them useful as indicator species in biodiversity studies.^[38][39]

Morphology

Ants are distinct in their morphology from other insects in having geniculate (elbowed) antennae, metapleural glands, and a strong constriction of their second abdominal segment into a node-like petiole. The body is divided into three distinct sections (formally known as tagmata): the head, mesosoma, and metasoma. The petiole forms a narrow waist between their mesosoma (thorax plus the first abdominal segment, which is fused to it) and gaster (abdomen less the abdominal segments in the petiole). The petiole may be formed by one or two nodes (the second alone, or the second and third abdominal segments).^[40] Tergosternal fusion, when the tergite and sternite of a segment fuse together, can occur partly or fully on the second, third and fourth abdominal segment and is used in identification. Fourth abdominal tergosternal fusion was formerly used as character that defined the poneromorph subfamilies, Ponerinae and relatives within their clade, but this is no longer considered a synapomorphic character.^[41]

Like other arthropods, ants have an exoskeleton, an external covering that provides a protective casing around the body and a point of attachment for muscles, in contrast to the internal skeletons of humans and other vertebrates. Insects do not have lungs; oxygen and other gases, such as carbon dioxide, pass through their exoskeleton via tiny valves called spiracles. Insects also lack closed blood vessels; instead, they have a long, thin, perforated tube along the top of the body (called the “dorsal aorta”) that functions like a heart, and pumps haemolymph toward the head, thus driving the circulation of the internal fluids. The nervous system consists of a ventral nerve cord that runs the length of the body, with several ganglia and branches along the way reaching into the extremities of the appendages.^[42]

Head

An ant’s head contains many sensory organs. Like most insects, ants have compound eyes made from numerous tiny lenses attached together. Ant eyes are good for acute movement detection, but do not offer a high resolution image. They also have three small ocelli (simple eyes) on the top of the head that detect light levels and polarization.^[43] Compared to vertebrates, ants tend to have blurrier eyesight, particularly in smaller species,^[44] and a few subterranean taxa are completely blind.^[12] However, some ants, such as Australia’s bulldog ant, have excellent vision and are capable of discriminating the distance and size of objects moving nearly a meter away.^[45] Based on experiments conducted to test their ability to differentiate between selected wavelengths of light, some ant species such as Camponotus blandus, Solenopsis invicta, and Formica cunicularia are thought to possess a degree of colour vision.^[46]

Two antennae (“feelers”) are attached to the head; these organs detect chemicals, air currents, and vibrations; they also are used to transmit and receive signals through touch. The head has two strong jaws, the mandibles, used to carry food, manipulate objects, construct nests, and for defence.^[42] In some species, a small pocket (infrabuccal chamber) inside the mouth stores food, so it may be passed to other ants or their larvae.^[47]

Mesosoma

Both the legs and wings of the ant are attached to the mesosoma (“thorax”). The legs terminate in a hooked claw which allows them to hook on and climb surfaces.^[48] Only reproductive ants (queens and males) have wings. Queens shed their wings after the nuptial flight, leaving visible stubs, a distinguishing feature of queens. In a few species, wingless queens (ergatoids) and males occur.^[42]

Metasoma

The metasoma (the “abdomen”) of the ant houses important internal organs, including those of the reproductive, respiratory (tracheae), and excretory systems. Workers of many species have their egg-laying structures modified into stings that are used for subduing prey and defending their nests.^[42]

Polymorphism

In the colonies of a few ant species, there are physical castes—workers in distinct size-classes, called minor (micrergates), median, and major ergates (macrergates). Often, the larger ants have disproportionately larger heads, and correspondingly stronger mandibles. Although formally known as dinergates, such individuals are sometimes called “soldier” ants because their stronger mandibles make them more effective in fighting, although they still are workers and their “duties” typically do not vary greatly from the minor or median workers.^[49] In a few species, the median workers are absent, creating a sharp divide between the minors and majors.^[50] Weaver ants, for example, have a distinct bimodal size distribution.^[51][52] Some other species show continuous variation in the size of workers. The smallest and largest workers in Carebara diversa show nearly a 500-fold difference in their dry weights.^[53]

Workers cannot mate; however, because of the haplodiploid sex-determination system in ants, workers of a number of species can lay unfertilised eggs that become fully fertile, haploid males. The role of workers may change with their age and in some species, such as honeypot ants, young workers are fed until their gasters are distended, and act as living food storage vessels. These food storage workers are called repletes.^[54] For instance, these replete workers develop in the North American honeypot ant Myrmecocystus mexicanus. Usually the largest workers in the colony develop into repletes; and, if repletes are removed from the colony, other workers become repletes, demonstrating the flexibility of this particular polymorphism.^[55] This polymorphism in morphology and behaviour of workers initially was thought to be determined by environmental factors such as nutrition and hormones that led to different developmental paths; however, genetic differences between worker castes have been noted in Acromyrmex sp.^[56] These polymorphisms are caused by relatively small genetic changes; differences in a single gene of Solenopsis invicta can decide whether the colony will have single or multiple queens.^[57] The Australian jack jumper ant (Myrmecia pilosula) has only a single pair of chromosomes (with the males having just one chromosome as they are haploid), the lowest number known for any animal, making it an interesting subject for studies in the genetics and developmental biology of social insects.^[58][59]

Genome size

Genome size is a fundamental characteristic of an organism. Ants have been found to have tiny genomes, with the evolution of genome size suggested to occur through loss and accumulation of non-coding regions, mainly transposable elements, and occasionally by whole genome duplication.^[60] This may be related to colonisation processes, but further studies are needed to verify this.^[60]

Life cycle

The life of an ant starts from an egg; if the egg is fertilised, the progeny will be female diploid, if not, it will be male haploid. Ants develop by complete metamorphosis with the larva stages passing through a pupal stage before emerging as an adult. The larva is largely immobile and is fed and cared for by workers. Food is given to the larvae by trophallaxis, a process in which an ant regurgitates liquid food held in its crop. This is also how adults share food, stored in the “social stomach”. Larvae, especially in the later stages, may also be provided solid food, such as trophic eggs, pieces of prey, and seeds brought by workers.^[61]

The larvae grow through a series of four or five moults and enter the pupal stage. The pupa has the appendages free and not fused to the body as in a butterfly pupa.^[62] The differentiation into queens and workers (which are both female), and different castes of workers, is influenced in some species by the nutrition the larvae obtain. Genetic influences and the control of gene expression by the developmental environment are complex and the determination of caste continues to be a subject of research.^[63] Winged male ants, called drones (termed “aner” in old literature^[49]), emerge from pupae along with the usually winged breeding females. Some species, such as army ants, have wingless queens. Larvae and pupae need to be kept at fairly constant temperatures to ensure proper development, and so often are moved around among the various brood chambers within the colony.^[64]

A new ergate spends the first few days of its adult life caring for the queen and young. She then graduates to digging and other nest work, and later to defending the nest and foraging. These changes are sometimes fairly sudden, and define what are called temporal castes. Such age-based task-specialization or polyethism has been suggested as having evolved due to the high casualties involved in foraging and defence, making it an acceptable risk only for ants who are older and likely to die sooner from natural causes.^[65][66] In the Brazilian ant Forelius pusillus, the nest entrance is closed from the outside to protect the colony from predatory ant species at sunset each day. About one to eight workers seal the nest entrance from the outside and they have no chance of returning to the nest and are in effect sacrificed.^[67] Whether these seemingly suicidal workers are older workers has not been determined.^[68]

Ant colonies can be long-lived. The queens can live for up to 30 years, and workers live from 1 to 3 years. Males, however, are more transitory, being quite short-lived and surviving for only a few weeks.^[69] Ant queens are estimated to live 100 times as long as solitary insects of a similar size.^[70]

Ants are active all year long in the tropics; however, in cooler regions, they survive the winter in a state of dormancy known as hibernation. The forms of inactivity are varied and some temperate species have larvae going into the inactive state (diapause), while in others, the adults alone pass the winter in a state of reduced activity.^[71]

Reproduction

A wide range of reproductive strategies have been noted in ant species. Females of many species are known to be capable of reproducing asexually through thelytokous parthenogenesis.^[72] Secretions from the male accessory glands in some species can plug the female genital opening and prevent females from re-mating.^[73] Most ant species have a system in which only the queen and breeding females have the ability to mate. Contrary to popular belief, some ant nests have multiple queens, while others may exist without queens. Workers with the ability to reproduce are called “gamergates” and colonies that lack queens are then called gamergate colonies; colonies with queens are said to be queen-right.^[74]

Drones can also mate with existing queens by entering a foreign colony, such as in army ants. When the drone is initially attacked by the workers, it releases a mating pheromone. If recognized as a mate, it will be carried to the queen to mate.^[75] Males may also patrol the nest and fight others by grabbing them with their mandibles, piercing their exoskeleton and then marking them with a pheromone. The marked male is interpreted as an invader by worker ants and is killed.^[76]

Most ants are univoltine, producing a new generation each year.^[77] During the species-specific breeding period, winged females and winged males, known to entomologists as alates, leave the colony in what is called a nuptial flight. The nuptial flight usually takes place in the late spring or early summer when the weather is hot and humid. Heat makes flying easier and freshly fallen rain makes the ground softer for mated queens to dig nests.^[78] Males typically take flight before the females. Males then use visual cues to find a common mating ground, for example, a landmark such as a pine tree to which other males in the area converge. Males secrete a mating pheromone that females follow. Males will mount females in the air, but the actual mating process usually takes place on the ground. Females of some species mate with just one male but in others they may mate with as many as ten or more different males, storing the sperm in their spermathecae.^[79] The genus Cardiocondyla have species with both winged and wingless males, where the latter will only mate with females living in the same nest. Some species in the genus have lost winged males completely, and only produce wingless males.^[80] In C. elegans, workers may transport newly emerged queens to other conspecific nests where the wingless males from unrelated colonies can mate with them, a behavioural adaptation that may reduce the chances of inbreeding.^[81]

Mated females then seek a suitable place to begin a colony. There, they break off their wings using their tibial spurs and begin to lay and care for eggs. The females can selectively fertilise future eggs with the sperm stored to produce diploid workers or lay unfertilized haploid eggs to produce drones. The first workers to hatch, known as nanitics,^[82] are weaker and smaller than later workers but they begin to serve the colony immediately. They enlarge the nest, forage for food, and care for the other eggs. Species that have multiple queens may have a queen leaving the nest along with some workers to found a colony at a new site,^[79] a process akin to swarming in honeybees.

Nests, colonies, and supercolonies

The typical ant species has a colony occupying a single nest, housing one or more queens, where the brood is raised. There are however more than 150 species of ants in 49 genera that are known to have colonies consisting of multiple spatially separated nests. These polydomous (as opposed to monodomous) colonies have food and workers moving between the nests.^[83] Membership to a colony is identified by the response of worker ants which identify whether another individual belongs to their own colony or not. A signature cocktail of body surface chemicals (also known as cuticular hydrocarbons or CHCs) forms the so-called colony odor which other members can recognize.^[84] Some ant species appear to be less discriminating and in the Argentine ant Linepithema humile, workers carried from a colony anywhere in the southern US and Mexico are acceptable within other colonies in the same region. Similarly workers from colonies that have established in Europe are accepted by any other colonies within Europe but not by the colonies in the Americas. The interpretation of these observations has been debated and some have been termed these large populations as supercolonies^[85][86][87] while others have termed the populations as unicolonial.^[88]

Behaviour and ecology

Communication

See also: Ant communication

Ants find a dying white cabbage larvae that parasitoid wasps larvae exited two days earlier.

Ants communicate with each other using pheromones, sounds, and touch.^[89] Since most ants live on the ground, they use the soil surface to leave pheromone trails that may be followed by other ants. In species that forage in groups, a forager that finds food marks a trail on the way back to the colony; this trail is followed by other ants, these ants then reinforce the trail when they head back with food to the colony. When the food source is exhausted, no new trails are marked by returning ants and the scent slowly dissipates. This behaviour helps ants deal with changes in their environment. For instance, when an established path to a food source is blocked by an obstacle, the foragers leave the path to explore new routes. If an ant is successful, it leaves a new trail marking the shortest route on its return. Successful trails are followed by more ants, reinforcing better routes and gradually identifying the best path.^[89][90]

Ants use pheromones for more than just making trails. A crushed ant emits an alarm pheromone that sends nearby ants into an attack frenzy and attracts more ants from farther away. Several ant species even use “propaganda pheromones” to confuse enemy ants and make them fight among themselves.^[91] Pheromones are produced by a wide range of structures including Dufour’s glands, poison glands and glands on the hindgut, pygidium, rectum, sternum, and hind tibia.^[70] Pheromones also are exchanged, mixed with food, and passed by trophallaxis, transferring information within the colony.^[92] This allows other ants to detect what task group (e.g., foraging or nest maintenance) other colony members belong to.^[93] In ant species with queen castes, when the dominant queen stops producing a specific pheromone, workers begin to raise new queens in the colony.^[94]

Some ants produce sounds by stridulation, using the gaster segments and their mandibles. Sounds may be used to communicate with colony members or with other species.^[95][96]

Defence

See also: Defense in insects

Ants attack and defend themselves by biting and, in many species, by stinging often injecting or spraying chemicals. Bullet ants (Paraponera), located in Central and South America, are considered to have the most painful sting of any insect, although it is usually not fatal to humans. This sting is given the highest rating on the Schmidt sting pain index.^[97]

The sting of jack jumper ants can be lethal for humans,^[98] and an antivenom has been developed for it.^[99] Fire ants, Solenopsis spp., are unique in having a venom sac containing piperidine alkaloids.^[100] Their stings are painful and can be dangerous to hypersensitive people.^[101] Formicine ants secrete a poison from their glands, made mainly of formic acid.^[102]

Trap-jaw ants of the genus Odontomachus are equipped with mandibles called trap-jaws, which snap shut faster than any other predatory appendages within the animal kingdom.^[103] One study of Odontomachus bauri recorded peak speeds of between 126 and 230 km/h (78 and 143 mph), with the jaws closing within 130 microseconds on average. The ants were also observed to use their jaws as a catapult to eject intruders or fling themselves backward to escape a threat.^[103] Before striking, the ant opens its mandibles extremely widely and locks them in this position by an internal mechanism. Energy is stored in a thick band of muscle and explosively released when triggered by the stimulation of sensory organs resembling hairs on the inside of the mandibles. The mandibles also permit slow and fine movements for other tasks. Trap-jaws also are seen in other ponerines such as Anochetus, as well as some genera in the tribe Attini, such as Daceton, Orectognathus, and Strumigenys,^[103][104] which are viewed as examples of convergent evolution.

A Malaysian species of ant in the Camponotus cylindricus group has enlarged mandibular glands that extend into their gaster. If combat takes a turn for the worse, a worker may perform a final act of suicidal altruism by rupturing the membrane of its gaster, causing the content of its mandibular glands to burst from the anterior region of its head, spraying a poisonous, corrosive secretion containing acetophenones and other chemicals that immobilise small insect attackers. The worker subsequently dies.^[105]

In addition to defence against predators, ants need to protect their colonies from pathogens. Secretions from the metapleural gland, unique to the ants, produce a complex range of chemicals including several with antibiotic properties.^[106] Some worker ants maintain the hygiene of the colony and their activities include undertaking or necrophoresis, the disposal of dead nest-mates.^[107] Oleic acid has been identified as the compound released from dead ants that triggers necrophoric behaviour in Atta mexicana^[108] while workers of Linepithema humile react to the absence of characteristic chemicals (dolichodial and iridomyrmecin) present on the cuticle of their living nestmates to trigger similar behaviour.^[109] In Megaponera analis, injured ants are treated by nestmastes with secretions from their metapleural glands which protect them from infection.^[110] Camponotus ants do not have a metapleural gland^[106] and Camponotus maculatus as well as C. floridanus workers have been found to amputate the affected legs of nestmates when the femur is injured. A femur injury carries a greater risk of infection unlike a tibia injury.^[111]

Nests may be protected from physical threats such as flooding and overheating by elaborate nest architecture.^[112][113] Workers of Cataulacus muticus, an arboreal species that lives in plant hollows, respond to flooding by drinking water inside the nest, and excreting it outside.^[114] Camponotus anderseni, which nests in the cavities of wood in mangrove habitats, deals with submergence under water by switching to anaerobic respiration.^[115]

Learning

Many animals can learn behaviours by imitation, but ants may be the only group apart from mammals where interactive teaching has been observed. A knowledgeable forager of Temnothorax albipennis can lead a naïve nest-mate to newly discovered food by the process of tandem running. The follower obtains knowledge through its leading tutor. The leader is acutely sensitive to the progress of the follower and slows down when the follower lags and speeds up when the follower gets too close.^[116]

Controlled experiments with colonies of Cerapachys biroi suggest that an individual may choose nest roles based on her previous experience. An entire generation of identical workers was divided into two groups whose outcome in food foraging was controlled. One group was continually rewarded with prey, while it was made certain that the other failed. As a result, members of the successful group intensified their foraging attempts while the unsuccessful group ventured out fewer and fewer times. A month later, the successful foragers continued in their role while the others had moved to specialise in brood care.^[117]

Nest construction

Main article: Ant colony

Complex nests are built by many ant species, but other species are nomadic and do not build permanent structures. Ants may form subterranean nests or build them on trees. These nests may be found in the ground, under stones or logs, inside logs, hollow stems, or even acorns. The materials used for construction include soil and plant matter,^[79] and ants carefully select their nest sites; Temnothorax albipennis will avoid sites with dead ants, as these may indicate the presence of pests or disease. They are quick to abandon established nests at the first sign of threats.^[118]

The army ants of South America, such as the Eciton burchellii species, and the driver ants of Africa do not build permanent nests, but instead, alternate between nomadism and stages where the workers form a temporary nest (bivouac) from their own bodies, by holding each other together.^[119]

Weaver ant (Oecophylla spp.) workers build nests in trees by attaching leaves together, first pulling them together with bridges of workers and then inducing their larvae to produce silk as they are moved along the leaf edges. Similar forms of nest construction are seen in some species of Polyrhachis.^[120]

Formica polyctena, among other ant species, constructs nests that maintain a relatively constant interior temperature that aids in the development of larvae. The ants maintain the nest temperature by choosing the location, nest materials, controlling ventilation and maintaining the heat from solar radiation, worker activity and metabolism, and in some moist nests, microbial activity in the nest materials.^[121][122]

Some ant species, such as those that use natural cavities, can be opportunistic and make use of the controlled micro-climate provided inside human dwellings and other artificial structures to house their colonies and nest structures.^[123][124]

Cultivation of food

Main article: Ant–fungus mutualism

Most ants are generalist predators, scavengers, and indirect herbivores,^[19] but a few have evolved specialised ways of obtaining nutrition. It is believed that many ant species that engage in indirect herbivory rely on specialized symbiosis with their gut microbes^[125] to upgrade the nutritional value of the food they collect^[126] and allow them to survive in nitrogen poor regions, such as rainforest canopies.^[127] Leafcutter ants (Atta and Acromyrmex) feed exclusively on a fungus that grows only within their colonies. They continually collect leaves which are taken to the colony, cut into tiny pieces and placed in fungal gardens. Ergates specialise in related tasks according to their sizes. The largest ants cut stalks, smaller workers chew the leaves and the smallest tend the fungus. Leafcutter ants are sensitive enough to recognise the reaction of the fungus to different plant material, apparently detecting chemical signals from the fungus. If a particular type of leaf is found to be toxic to the fungus, the colony will no longer collect it. The ants feed on structures produced by the fungi called gongylidia. Symbiotic bacteria on the exterior surface of the ants produce antibiotics that kill bacteria introduced into the nest that may harm the fungi.^[128]

Navigation

Foraging ants travel distances of up to 200 metres (700 ft) from their nest^[129] and scent trails allow them to find their way back even in the dark. In hot and arid regions, day-foraging ants face death by desiccation, so the ability to find the shortest route back to the nest reduces that risk. Diurnal desert ants of the genus Cataglyphis such as the Sahara desert ant navigate by keeping track of direction as well as distance travelled. Distances travelled are measured using an internal pedometer that keeps count of the steps taken^[130] and also by evaluating the movement of objects in their visual field (optical flow).^[131] Directions are measured using the position of the sun.^[132] They integrate this information to find the shortest route back to their nest.^[133] Like all ants, they can also make use of visual landmarks when available^[134] as well as olfactory and tactile cues to navigate.^[135][136] Some species of ant are able to use the Earth’s magnetic field for navigation.^[137] The compound eyes of ants have specialised cells that detect polarised light from the Sun, which is used to determine direction.^[138][139] These polarization detectors are sensitive in the ultraviolet region of the light spectrum.^[140] In some army ant species, a group of foragers who become separated from the main column may sometimes turn back on themselves and form a circular ant mill. The workers may then run around continuously until they die of exhaustion.^[141]

Locomotion

The female worker ants do not have wings and reproductive females lose their wings after their mating flights in order to begin their colonies. Therefore, unlike their wasp ancestors, most ants travel by walking. Some species are capable of leaping. For example, Jerdon’s jumping ant (Harpegnathos saltator) is able to jump by synchronising the action of its mid and hind pairs of legs.^[142] There are several species of gliding ant including Cephalotes atratus; this may be a common trait among arboreal ants with small colonies. Ants with this ability are able to control their horizontal movement so as to catch tree trunks when they fall from atop the forest canopy.^[143]

Other species of ants can form chains to bridge gaps over water, underground, or through spaces in vegetation. Some species also form floating rafts that help them survive floods.^[144] These rafts may also have a role in allowing ants to colonise islands.^[145] Polyrhachis sokolova, a species of ant found in Australian mangrove swamps, can swim and live in underwater nests. Since they lack gills, they go to trapped pockets of air in the submerged nests to breathe.^[146]

Cooperation and competition

Not all ants have the same kind of societies. The Australian bulldog ants are among the biggest and most basal of ants. Like virtually all ants, they are eusocial, but their social behaviour is poorly developed compared to other species. Each individual hunts alone, using her large eyes instead of chemical senses to find prey.^[147]

Some species attack and take over neighbouring ant colonies. Extreme specialists among these slave-raiding ants, such as the Amazon ants, are incapable of feeding themselves and need captured workers to survive.^[148] Captured workers of enslaved Temnothorax species have evolved a counter-strategy, destroying just the female pupae of the slave-making Temnothorax americanus, but sparing the males (who do not take part in slave-raiding as adults).^[149]

Ants identify kin and nestmates through their scent, which comes from hydrocarbon-laced secretions that coat their exoskeletons. If an ant is separated from its original colony, it will eventually lose the colony scent. Any ant that enters a colony without a matching scent will be attacked.^[150]

Parasitic ant species enter the colonies of host ants and establish themselves as social parasites; species such as Strumigenys xenos are entirely parasitic and do not have workers, but instead, rely on the food gathered by their Strumigenys perplexa hosts.^[151][152] This form of parasitism is seen across many ant genera, but the parasitic ant is usually a species that is closely related to its host. A variety of methods are employed to enter the nest of the host ant. A parasitic queen may enter the host nest before the first brood has hatched, establishing herself prior to development of a colony scent. Other species use pheromones to confuse the host ants or to trick them into carrying the parasitic queen into the nest. Some simply fight their way into the nest.^[153]

A conflict between the sexes of a species is seen in some species of ants with these reproducers apparently competing to produce offspring that are as closely related to them as possible. The most extreme form involves the production of clonal offspring. An extreme of sexual conflict is seen in Wasmannia auropunctata, where the queens produce diploid daughters by thelytokous parthenogenesis and males produce clones by a process whereby a diploid egg loses its maternal contribution to produce haploid males who are clones of the father.^[154]

Relationships with other organisms

Ants form symbiotic associations with a range of species, including other ant species, other insects, plants, and fungi. They also are preyed on by many animals and even certain fungi. Some arthropod species spend part of their lives within ant nests, either preying on ants, their larvae, and eggs, consuming the food stores of the ants, or avoiding predators. These inquilines may bear a close resemblance to ants. The nature of this ant mimicry (myrmecomorphy) varies, with some cases involving Batesian mimicry, where the mimic reduces the risk of predation. Others show Wasmannian mimicry, a form of mimicry seen only in inquilines.^[155][156]

Duration: 2 minutes and 9 seconds.2:09Ants collecting honeydew from Calico scales (Eulecanium cerasorum) then played at 30 times speed to show the pumping action of the scale.

Aphids and other hemipteran insects secrete a sweet liquid called honeydew, when they feed on plant sap. The sugars in honeydew are a high-energy food source, which many ant species collect.^[157] In some cases, the aphids secrete the honeydew in response to ants tapping them with their antennae. The ants in turn keep predators away from the aphids and will move them from one feeding location to another. When migrating to a new area, many colonies will take the aphids with them, to ensure a continued supply of honeydew. Ants also tend mealybugs to harvest their honeydew. Mealybugs may become a serious pest of pineapples if ants are present to protect mealybugs from their natural enemies.^[158]

Myrmecophilous (ant-loving) caterpillars of the butterfly family Lycaenidae (e.g., blues, coppers, or hairstreaks) are herded by the ants, led to feeding areas in the daytime, and brought inside the ants’ nest at night. The caterpillars have a gland which secretes honeydew when the ants massage them. The chemicals in the secretions of Narathura japonica alter the behavior of attendant Pristomyrmex punctatus workers, making them less aggressive and stationary. The relationship, formerly characterized as “mutualistic”, is now considered as possibly a case of the ants being parasitically manipulated by the caterpillars.^[159] Some caterpillars produce vibrations and sounds that are perceived by the ants.^[160] A similar adaptation can be seen in Grizzled skipper butterflies that emit vibrations by expanding their wings in order to communicate with ants, which are natural predators of these butterflies.^[161] Other caterpillars have evolved from ant-loving to ant-eating: these myrmecophagous caterpillars secrete a pheromone that makes the ants act as if the caterpillar is one of their own larvae. The caterpillar is then taken into the ant nest where it feeds on the ant larvae.^[162] A number of specialized bacteria have been found as endosymbionts in ant guts. Some of the dominant bacteria belong to the order Hyphomicrobiales whose members are known for being nitrogen-fixing symbionts in legumes but the species found in ant lack the ability to fix nitrogen.^[163][164] Fungus-growing ants that make up the tribe Attini, including leafcutter ants, cultivate certain species of fungus in the genera Leucoagaricus or Leucocoprinus of the family Agaricaceae. In this ant-fungus mutualism, both species depend on each other for survival. The ant Allomerus decemarticulatus has evolved a three-way association with the host plant, Hirtella physophora (Chrysobalanaceae), and a sticky fungus which is used to trap their insect prey.^[165]

Ants tending aphids and collecting honeydew secreted. A wrinkled solder beetle flies in and eats an aphid before being chased away by the ants.

Lemon ants make devil’s gardens by killing surrounding plants with their stings and leaving a pure patch of lemon ant trees, (Duroia hirsuta). This modification of the forest provides the ants with more nesting sites inside the stems of the Duroia trees.^[166] Although some ants obtain nectar from flowers, pollination by ants is somewhat rare, one example being of the pollination of the orchid Leporella fimbriata which induces male Myrmecia urens to pseudocopulate with the flowers, transferring pollen in the process.^[167] One theory that has been proposed for the rarity of pollination is that the secretions of the metapleural gland inactivate and reduce the viability of pollen.^[168][169] Some plants, mostly angiosperms but also some ferns,^[170] have special nectar exuding structures, extrafloral nectaries, that provide food for ants, which in turn protect the plant from more damaging herbivorous insects.^[171] Species such as the bullhorn acacia (Acacia cornigera) in Central America have hollow thorns that house colonies of stinging ants (Pseudomyrmex ferruginea) who defend the tree against insects, browsing mammals, and epiphytic vines. Isotopic labelling studies suggest that plants also obtain nitrogen from the ants.^[172] In return, the ants obtain food from protein- and lipid-rich Beltian bodies. In Fiji Philidris nagasau (Dolichoderinae) are known to selectively grow species of epiphytic Squamellaria (Rubiaceae) which produce large domatia inside which the ant colonies nest. The ants plant the seeds and the domatia of young seedling are immediately occupied and the ant faeces in them contribute to rapid growth.^[173] Similar dispersal associations are found with other dolichoderines in the region as well.^[174] Another example of this type of ectosymbiosis comes from the Macaranga tree, which has stems adapted to house colonies of Crematogaster ants.^[175]

Many plant species have seeds that are adapted for dispersal by ants.^[176] Seed dispersal by ants or myrmecochory is widespread, and new estimates suggest that nearly 9% of all plant species may have such ant associations.^[177][176] Often, seed-dispersing ants perform directed dispersal, depositing the seeds in locations that increase the likelihood of seed survival to reproduction.^[178] Some plants in arid, fire-prone systems are particularly dependent on ants for their survival and dispersal as the seeds are transported to safety below the ground.^[179] Many ant-dispersed seeds have special external structures, elaiosomes, that are sought after by ants as food.^[180] Ants can substantially alter rate of decomposition and nutrient cycling in their nest.^[181][182] By myrmecochory and modification of soil conditions they substantially alter vegetation and nutrient cycling in surrounding ecosystem.^[183]

A convergence, possibly a form of mimicry, is seen in the eggs of stick insects. They have an edible elaiosome-like structure and are taken into the ant nest where the young hatch.^[184]

Bold Jumping Spider (Phidippus audax) with a cutworm (tribe Noctuini) and then lost to ants (Family Formicidae)Ants from different colonies steal the cranefly that a pair of Long-jawed orb weaver spiders were consuming.

Most ants are predatory and some prey on and obtain food from other social insects including other ants. Some species specialise in preying on termites (Megaponera and Termitopone) while a few Cerapachyinae prey on other ants.^[129] Some termites, including Nasutitermes corniger, form associations with certain ant species to keep away predatory ant species.^[185] The tropical wasp Mischocyttarus drewseni coats the pedicel of its nest with an ant-repellent chemical.^[186] It is suggested that many tropical wasps may build their nests in trees and cover them to protect themselves from ants. Other wasps, such as A. multipicta, defend against ants by blasting them off the nest with bursts of wing buzzing.^[187] Stingless bees (Trigona and Melipona) use chemical defences against ants.^[129]

Flies in the Old World genus Bengalia (Calliphoridae) prey on ants and are kleptoparasites, snatching prey or brood from the mandibles of adult ants.^[188] Wingless and legless females of the Malaysian phorid fly (Vestigipoda myrmolarvoidea) live in the nests of ants of the genus Aenictus and are cared for by the ants.^[188]

Fungi in the genera Cordyceps and Ophiocordyceps infect ants. Ants react to their infection by climbing up plants and sinking their mandibles into plant tissue. The fungus kills the ants, grows on their remains, and produces a fruiting body. It appears that the fungus alters the behaviour of the ant to help disperse its spores^[189] in a microhabitat that best suits the fungus.^[190] Strepsipteran parasites also manipulate their ant host to climb grass stems, to help the parasite find mates.^[191]

A nematode (Myrmeconema neotropicum) that infects canopy ants (Cephalotes atratus) causes the black-coloured gasters of workers to turn red. The parasite also alters the behaviour of the ant, causing them to carry their gasters high. The conspicuous red gasters are mistaken by birds for ripe fruits, such as Hyeronima alchorneoides, and eaten. The droppings of the bird are collected by other ants and fed to their young, leading to further spread of the nematode.^[192]

A study of Temnothorax nylanderi colonies in Germany found that workers parasitized by the tapeworm Anomotaenia brevis (ants are intermediate hosts, the definitive hosts are woodpeckers) lived much longer than unparasitized workers and had a reduced mortality rate, comparable to that of the queens of the same species, which live for as long as two decades.^[193]

South American poison dart frogs in the genus Dendrobates feed mainly on ants, and the toxins in the skin of some species come from the ants.^[194][195] Formicine ants in the genera Brachymyrmex and Paratrechina have been found to contain pumiliotoxin found in Dendrobates pumilio.^[196] The West African frog Phrynomantis microps is able to move within the nests of Paltothyreus tarsatus ants, producing peptides on its skin that prevent the ants from stinging them.^[197]

Army ants which is the toxin found in forage in a wide roving column, attacking any animals in that path that are unable to escape. In Central and South America, Eciton burchellii is the swarming ant most commonly attended by “ant-following” birds such as antbirds and woodcreepers.^[198][199] This behaviour was once considered mutualistic, but later studies found the birds to be parasitic. Direct kleptoparasitism (birds stealing food from the ants’ grasp) is rare and has been noted in Inca doves which pick seeds at nest entrances as they are being transported by species of Pogonomyrmex.^[200] Birds that follow ants eat many prey insects and thus decrease the foraging success of ants.^[201] Birds indulge in a peculiar behaviour called anting that, as yet, is not fully understood. Here birds rest on ant nests, or pick and drop ants onto their wings and feathers; this may be a means to remove ectoparasites from the birds.

Anteaters, aardvarks, pangolins, echidnas and numbats have special adaptations for living on a diet of ants. These adaptations include long, sticky tongues to capture ants and strong claws to break into ant nests. Brown bears (Ursus arctos) have been found to feed on ants. About 12%, 16%, and 4% of their faecal volume in spring, summer and autumn, respectively, is composed of ants.^[202]

Relationship with humans

Ants perform many ecological roles that are beneficial to humans, including the suppression of pest populations and aeration of the soil. The use of weaver ants in citrus cultivation in southern China is considered one of the oldest known applications of biological control.^[203] On the other hand, ants may become nuisances when they invade buildings or cause economic losses.

In some parts of the world (mainly Africa and South America), large ants, especially army ants, are used as surgical sutures. The wound is pressed together and ants are applied along it. The ant seizes the edges of the wound in its mandibles and locks in place. The body is then cut off and the head and mandibles remain in place to close the wound.^{[204][205][206]} The large heads of the dinergates (soldiers) of the leafcutting ant Atta cephalotes are also used by native surgeons in closing wounds.^[207]

Some ants have toxic venom and are of medical importance. The species include Paraponera clavata (tocandira) and Dinoponera spp. (false tocandiras) of South America^[208] and the Myrmecia ants of Australia.^[209]

In South Africa, ants are used to help harvest the seeds of rooibos (Aspalathus linearis), a plant used to make a herbal tea. The plant disperses its seeds widely, making manual collection difficult. Black ants collect and store these and other seeds in their nest, where humans can gather them en masse. Up to half a pound (200 g) of seeds may be collected from one ant-heap.^[210][211]

Although most ants survive attempts by humans to eradicate them, a few are highly endangered. These tend to be island species that have evolved specialized traits and risk being displaced by introduced ant species. Examples include the critically endangered Sri Lankan relict ant (Aneuretus simoni) and Adetomyrma venatrix of Madagascar.^[212]

As food

See also: Entomophagy

Ants and their larvae are eaten in different parts of the world. The eggs of two species of ants are used in Mexican escamoles. They are considered a form of insect caviar and can sell for as much as US$50 per kg going up to US$200 per kg (as of 2006) because they are seasonal and hard to find.^[213] In the Colombian department of Santander, hormigas culonas (roughly interpreted as “large-bottomed ants”) Atta laevigata are toasted alive and eaten.^[214] In areas of India, and throughout Burma and Thailand, a paste of the green weaver ant (Oecophylla smaragdina) is served as a condiment with curry.^[215] Weaver ant eggs and larvae, as well as the ants, may be used in a Thai salad, yam (Thai: ยำ), in a dish called yam khai mot daeng (Thai: ยำไข่มดแดง) or red ant egg salad, a dish that comes from the Issan or north-eastern region of Thailand. Saville-Kent, in the Naturalist in Australia wrote “Beauty, in the case of the green ant, is more than skin-deep. Their attractive, almost sweetmeat-like translucency possibly invited the first essays at their consumption by the human species”. Mashed up in water, after the manner of lemon squash, “these ants form a pleasant acid drink which is held in high favor by the natives of North Queensland, and is even appreciated by many European palates”.^[216] Ants or their pupae are used as starters for yogurt making in parts of Bulgaria and Turkey.^[217]

In his First Summer in the Sierra, John Muir notes that the Digger Indians of California ate the tickling, acid gasters of the large jet-black carpenter ants. The Mexican Indians eat the repletes, or living honey-pots, of the honey ant (Myrmecocystus).^[216]

As pests

See also: Ants of medical importance

Some ant species are considered as pests, primarily those that occur in human habitations, where their presence is often problematic. For example, the presence of ants would be undesirable in sterile places such as hospitals or kitchens. Some species or genera commonly categorized as pests include the Argentine ant, immigrant pavement ant, yellow crazy ant, banded sugar ant, pharaoh ant, red wood ant, black carpenter ant, odorous house ant, red imported fire ant, and European fire ant. Some ants will raid stored food, some will seek water sources, others may damage indoor structures, some may damage agricultural crops directly or by aiding sucking pests. Some will sting or bite.^[218] The adaptive nature of ant colonies make it nearly impossible to eliminate entire colonies and most pest management practices aim to control local populations and tend to be temporary solutions. Ant populations are managed by a combination of approaches that make use of chemical, biological, and physical methods. Chemical methods include the use of insecticidal bait which is gathered by ants as food and brought back to the nest where the poison is inadvertently spread to other colony members through trophallaxis. Management is based on the species and techniques may vary according to the location and circumstance.^[218]

In science and technology

See also: Myrmecology, Biomimetics, and Ant colony optimization algorithms

Observed by humans since the dawn of history, the behaviour of ants has been documented and the subject of early writings and fables passed from one century to another. Those using scientific methods, myrmecologists, study ants in the laboratory and in their natural conditions. Their complex and variable social structures have made ants ideal model organisms. Ultraviolet vision was first discovered in ants by Sir John Lubbock in 1881.^[219] Studies on ants have tested hypotheses in ecology and sociobiology, and have been particularly important in examining the predictions of theories of kin selection and evolutionarily stable strategies.^[220] Ant colonies may be studied by rearing or temporarily maintaining them in formicaria, specially constructed glass framed enclosures.^[221] Individuals may be tracked for study by marking them with dots of colours.^[222]

The successful techniques used by ant colonies have been studied in computer science and robotics to produce distributed and fault-tolerant systems for solving problems, for example Ant colony optimization and Ant robotics. This area of biomimetics has led to studies of ant locomotion, search engines that make use of “foraging trails”, fault-tolerant storage, and networking algorithms.^[223]

As pets

Main article: Ant-keeping

From the late 1950s through the late 1970s, ant farms were popular educational children’s toys in the United States. Some later commercial versions use transparent gel instead of soil, allowing greater visibility at the cost of stressing the ants with unnatural light.^[224]

In culture

Anthropomorphised ants have often been used in fables, children’s stories, and religious texts to represent industriousness and cooperative effort, such as in the Aesop fable The Ant and the Grasshopper.^[225][226] In the Quran, Sulayman is said to have heard and understood an ant warning other ants to return home to avoid being accidentally crushed by Sulayman and his marching army.^{[Quran 27:18]},^[227][228] In parts of Africa, ants are considered to be the messengers of the deities. Some Native American mythology, such as the Hopi mythology, considers ants as the first animals. Ant bites are often said to have curative properties. The sting of some species of Pseudomyrmex is claimed to give fever relief.^[229] Ant bites are used in the initiation ceremonies of some Amazon Indian cultures as a test of endurance.^[230][231] In Greek mythology, the goddess Athena turned the maiden Myrmex into an ant when the latter claimed to have invented the plough, when in fact it was Athena’s own invention.^[232]

Ant society has always fascinated humans and has been written about both humorously and seriously. Mark Twain wrote about ants in his 1880 book A Tramp Abroad.^[233] Some modern authors have used the example of the ants to comment on the relationship between society and the individual. Examples are Robert Frost in his poem “Departmental” and T. H. White in his fantasy novel The Once and Future King. The plot in French entomologist and writer Bernard Werber‘s Les Fourmis science-fiction trilogy is divided between the worlds of ants and humans; ants and their behaviour are described using contemporary scientific knowledge. H. G. Wells wrote about intelligent ants destroying human settlements in Brazil and threatening human civilization in his 1905 science-fiction short story, The Empire of the Ants. A similar German story involving army ants, Leiningen Versus the Ants, was written in 1937 and recreated in movie form as The Naked Jungle in 1954.^[234] In more recent times, animated cartoons and 3-D animated films featuring ants have been produced including Antz, A Bug’s Life, The Ant Bully, The Ant and the Aardvark, Ferdy the Ant and Atom Ant. Renowned myrmecologist E. O. Wilson wrote a short story, “Trailhead” in 2010 for The New Yorker magazine, which describes the life and death of an ant-queen and the rise and fall of her colony, from an ants’ point of view.^[235]

Ants also are quite popular inspiration for many science-fiction insectoids, such as the Formics of Ender’s Game, the Bugs of Starship Troopers, the giant ants in the films Them! and Empire of the Ants, Marvel Comics‘ super hero Ant-Man, and ants mutated into super-intelligence in Phase IV. In computer strategy games, ant-based species often benefit from increased production rates due to their single-minded focus, such as the Klackons in the Master of Orion series of games or the ChCht in Deadlock II. These characters are often credited with a hive mind, a common misconception about ant colonies.^[236] In the early 1990s, the video game SimAnt, which simulated an ant colony, won the 1992 Codie award for “Best Simulation Program”.