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.
Lasius is a genus of formicine ants. The type species for this genus is the black garden ant, Lasius niger. Other major members, which live in drier heathland, are the cornfield ant, L. neoniger, and L. alienus. Other species include the temporary social parasites of the L. mixtus group and the hyper-social parasite Lasius fuliginosus. Lasius flavus is also a commonly seen species, building grassy hillocks in undisturbed pasture. In the Alps, these mounds – always aligned east to catch the first rays of the rising sun – have been traditionally used by goatherds as natural compasses. Species in the subgenus Acanthomyops, in particular L. interjectus and L. claviger, are commonly known as citronella ants due to their citronella-like smell.
Leafcutter ants, a non-generic name, are any of 47 species of leaf-chewing ants belonging to the two genera Atta and Acromyrmex, within the tribe Attini. These species of tropical, fungus-growing ants are all endemic to South and Central America, Mexico, and parts of the southern United States. Leafcutter ants can carry twenty times their body weight and cut and process fresh vegetation to serve as the nutritional substrate for their fungal cultivates.
The black garden ant, also known as the common black ant, is a formicine ant, the type species of the subgenus Lasius, which is found across Europe and in some parts of North America, South America, Asia and Australasia. The European species was split into two species; L. niger, which are found in open areas; and L. platythorax, which is found in forest habitats. It is monogynous, meaning colonies contain a single queen.
Fungus-growing ants comprise all the known fungus-growing ant species participating in ant–fungus mutualism. They are known for cutting grasses and leaves, carrying them to their colonies' nests, and using them to grow fungus on which they later feed.
An ant colony is a population of ants, typically from a single species, capable of maintaining their complete lifecycle. Ant colonies are eusocial, communal, and efficiently organized and are very much like those found in other social Hymenoptera, though the various groups of these developed sociality independently through convergent evolution. The typical colony consists of one or more egg-laying queens, numerous sterile females and, seasonally, many winged sexual males and females. In order to establish new colonies, ants undertake flights that occur at species-characteristic times of the day. Swarms of the winged sexuals depart the nest in search of other nests. The males die shortly thereafter, along with most of the females. A small percentage of the females survive to initiate new nests.
Carpenter ants are large ants indigenous to many forested parts of the world.
The pharaoh ant is a small (2 mm) yellow or light brown, almost transparent ant notorious for being a major indoor nuisance pest, especially in hospitals. A cryptogenic species, it has now been introduced to virtually every area of the world, including Europe, the Americas, Australasia and Southeast Asia. It is a major pest in the United States, Australia, and Europe. The ant's common name is possibly derived from the mistaken belief that it was one of the Egyptian (pharaonic) plagues.
Tapinoma sessile is a species of small ant that goes by the common names odorous house ant, sugar ant, stink ant, and coconut ant. Their colonies are polydomous and polygynous. Like many social insects, T. sessile employs complex foraging strategies, allocates food depending on environmental conditions, and engages in competition with other insects.
The yellow meadow ant, also known as the yellow hill ant, is a species of ant occurring in Europe, Asia, and North Africa. Populations in North America are now considered a different, related species, Lasius brevicornis.
Lasius umbratus, colloquially known as the yellow shadow ant and yellow lawn ant, is a Palearctic species of parasitic ant distributed across Eurasia and the Maghreb region of Africa. It was once thought that this species occurred in North America as well, but comparative genomic studies indicate the Afro-Eurasian and American populations are discrete and not closely related enough to represent a single species. The North American populations are now treated as a different species, Lasius aphidicola.
The Argentine ant is an ant native to northern Argentina, Uruguay, Paraguay, Bolivia and southern Brazil. This invasive species was inadvertently introduced by humans on a global scale and has become established in many Mediterranean climate areas, including South Africa, New Zealand, Japan, Easter Island, Australia, the Azores, Europe, Hawaii, and the continental United States. Argentine ants are significant pests within agricultural and urban settings, and are documented to cause substantial harm to communities of native arthropods, vertebrates, and plants within their invaded range.
Lasius alienus, or cornfield ant, is a species of ant in the subfamily Formicinae. Workers have a length of about 2–4 mm, Queens are larger (7–9 mm).
Slave-making ants or slaver ants are brood parasites that capture broods of other ant species to increase the worker force of their colony. After emerging in the slave-maker nest, slave workers work as if they were in their own colony, while parasite workers only concentrate on replenishing the labor force from neighboring host nests, a process called slave raiding.
Eusocial insects have developed from their organization an ability to recognize one another within their society. This recognition of others, from recognizing individuals to groups, is an indication of society, and creates an identity colony wide for each insect.
Lasius neoniger, also known as the turfgrass ant, Labour day ant, cornfield ant or nuisance ant, is a species of ant in the genus Lasius. Found in North America, the species is common in the eastern United States and Canada, though they can be found all over the continent. They are usually light brown in color, with a slightly darker head.
Social immunity is any antiparasite defence mounted for the benefit of individuals other than the actor. For parasites, the frequent contact, high population density and low genetic variability makes social groups of organisms a promising target for infection: this has driven the evolution of collective and cooperative anti-parasite mechanisms that both prevent the establishment of and reduce the damage of diseases among group members. Social immune mechanisms range from the prophylactic, such as burying beetles smearing their carcasses with antimicrobials or termites fumigating their nests with naphthalene, to the active defenses seen in the imprisoning of parasitic beetles by honeybees or by the miniature 'hitchhiking' leafcutter ants which travel on larger worker's leaves to fight off parasitoid flies. Whilst many specific social immune mechanisms had been studied in relative isolation, it was not until Sylvia Cremer et al.'s 2007 paper "Social Immunity" that the topic was seriously considered. Empirical and theoretical work in social immunity continues to reveal not only new mechanisms of protection but also implications for understanding of the evolution of group living and polyandry.
The social networks of colonies of social insects have been extensively studied as model biological networks.
An ant supercolony is an exceptionally large ant colony, consisting of a high number of spatially separated but socially connected nests of a single ant species, spread over a large area without territorial borders. Supercolonies are typically polygynous, containing many egg-laying females. Workers and queens from different nests within the same supercolony can freely move among the nests, and all workers cooperate indiscriminately with each other in collecting food and care of the brood, and show no apparent mutual aggressive behavior.
