Communication '' workers communicating through touch and pheromones larvae that
parasitoid wasps larvae exited two days earlier. Ants communicate with each other using
pheromones, sounds, and touch. 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. 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. 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. This allows other ants to detect what task group (e.g., foraging or nest maintenance) other colony members belong to. In ant species with queen
castes, when the dominant queen stops producing a specific pheromone, workers begin to raise new queens in the colony. 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.
Defence '' sp. attacks another of its kind to protect its territory. 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. The sting of
jack jumper ants can be lethal for humans, and an
antivenom has been developed for it.
Fire ants,
Solenopsis spp., are unique in having a venom sac containing
piperidine alkaloids. Their stings are painful and can be dangerous to hypersensitive people.
Formicine ants secrete a poison from their glands, made mainly of
formic acid. in fighting position,
mandibles wide open 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. One study of
Odontomachus bauri recorded peak speeds of between , 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. 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. 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. Some worker ants maintain the hygiene of the colony and their activities include
undertaking or
necrophoresis, the disposal of dead nest-mates.
Oleic acid has been identified as the compound released from dead ants that triggers necrophoric behaviour in
Atta mexicana 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. In
Megaponera analis, injured ants are treated by nestmastes with secretions from their metapleural glands which protect them from infection.
Camponotus ants do not have a metapleural gland Nests may be protected from physical threats such as flooding and overheating by elaborate nest architecture. 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.
Camponotus anderseni, which nests in the cavities of wood in mangrove habitats, deals with submergence under water by switching to
anaerobic respiration.
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. 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.
Nest construction ,
Pamalican,
Philippines 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, 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.
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.
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. 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.
Cultivation of food '',
honeypot ants, store food to prevent colony famine. Most ants are generalist predators,
scavengers, and indirect
herbivores, to upgrade the nutritional value of the food they collect and allow them to survive in nitrogen poor regions, such as rainforest canopies.
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.
Navigation Foraging ants travel distances of up to from their nest 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 and also by evaluating the movement of objects in their visual field (
optical flow). Directions are measured using the position of the sun. They
integrate this information to find the shortest route back to their nest. Like all ants, they can also make use of visual landmarks when available as well as olfactory and tactile cues to navigate. Some species of ant are able to use the
Earth's magnetic field for navigation. 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.
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. 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. 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. These rafts may also have a role in allowing ants to colonise islands.
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.
Cooperation and competition feeding on a
cicada: social ants cooperate and collectively gather food 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. 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. 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). '' (a jumping ant) engaged in battle with a rival colony's queen (on top) 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. 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. 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. 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.
Relationships with other organisms '' (female shown) mimics
weaver ants to avoid predators. 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. from an
aphid s 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. 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.
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
Arhopala 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. Some caterpillars produce vibrations and sounds that are perceived by the ants. 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. 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. 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.
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. '' workers, may obtain nectar from flowers such as the
dandelion, but are only rarely known to pollinate flowers. s 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. 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. 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. Some plants, mostly angiosperms but also some ferns, have special nectar exuding structures,
extrafloral nectaries, that provide food for ants, which in turn
protect the plant from more damaging
herbivorous insects. 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. 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. Similar dispersal associations are found with other dolichoderines in the region as well. Another example of this type of
ectosymbiosis comes from the
Macaranga tree, which has stems adapted to house colonies of
Crematogaster ants. Many plant species have seeds that are adapted for dispersal by ants.
Seed dispersal by ants or
myrmecochory is widespread, and new estimates suggest that nearly 9% of all plant species may have such ant associations. 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. Many ant-dispersed seeds have special external structures,
elaiosomes, that are sought after by ants as food. Ants can substantially alter rate of decomposition and nutrient cycling in their nest. By myrmecochory and modification of soil conditions they substantially alter vegetation and nutrient cycling in surrounding ecosystem. 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. tending a common
leafhopper nymph '') with a cutworm (tribe
Noctuini) and then lost to ants (Family Formicidae) s 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
Neoponera) while a few Cerapachyinae prey on other ants. The tropical wasp
Mischocyttarus drewseni coats the pedicel of its nest with an ant-repellent chemical. 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. Stingless bees (
Trigona and
Melipona) use chemical defences against ants. 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. in a microhabitat that best suits the fungus.
Strepsipteran parasites also manipulate their ant host to climb grass stems, to help the parasite find mates. 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. '' jumping spider) sometimes feed on ants|right 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. 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. Formicine ants in the genera
Brachymyrmex and
Paratrechina have been found to contain
pumiliotoxin found in
Dendrobates pumilio. 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.
Army ants 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. 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. Birds that follow ants eat many prey insects and thus decrease the foraging success of ants. 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. ==Relationship with humans==