Anthill
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An ant colony is an underground lair where ants live. Colonies consist of a series of underground chambers, connected to each other and the surface of the earth by small tunnels. There are rooms for nurseries, food storage, and mating. The colony is built and maintained by legions of worker ants, who carry tiny bits of dirt in their mandibles and deposit them near the exit of the colony, forming an ant-hill.

Ant colonies are eusocial, and are very much like those found in other social Hymenoptera, though the various groups of these developed sociality independently through convergent evolution. Eggs are laid by one or sometimes more queens. Queens are different in structure, they are the largest ones among all ants, especially their abdomen and thorax which are larger than most ants'. Their tasks are to lay eggs and produce more offspring. Most of the eggs that are laid by the queens grow up to become wingless, sterile females called "workers". Periodically, swarms of new winged queens and males (the alates) are produced in most species, which leave to mate. The males die shortly thereafter, while the surviving queens either found new colonies or occasionally return to their old one. The surviving queens can live up to around 15 years.

People raise ant colonies in captivity for research and as a hobby. An "ant terrarium" used for this purpose is called a formicarium. They are often made thin enough that you can see the entire colony inside their nest. These are also called ant farms.

Unicoloniality and supercolonies

Most commonly, ants from different nests exhibit aggression towards each other. However, some ants exhibit the phenomenon called unicoloniality: worker ants may freely mix between different nests. Another organization is supercoloniality. The group of nests where ants do not exhibit mutual aggression is called supercolony, while ants from different supercolonies of the same species do exhibit mutual aggression. Populations in supercolonies do not necessarily span a contiguous area. ^[1]

Until 2000, the largest known ant supercolony was on the Ishikari coast of Hokkaidō, Japan. The colony was estimated to contain 306 million worker ants and one million queen ants living in 45,000 nests interconnected by underground passages over an area of 2.7 km².^[2]

In 2000, an enormous supercolony of Argentine ants was found in Southern Europe (report published in 2002). Of 33 ant populations tested along the 6,004 km stretch along the Mediterranean and Atlantic coasts in Southern Europe 30 belonged to one supercolony with estimated millions of nests and billions of workers, interspersed with three populations of another supercolony.^[1] The researchers claim that this case of unicoloniality cannot be explained by loss of their genetic diversity due to the genetic bottleneck of the imported ants.

Another supercolony, measuring approximately 100 km wide, was found beneath Melbourne, Australia in 2004.^[3]

Ant-hills

A clay ant hill

An ant-hill, in its simplest form, is a pile of earth, sand, pine needles, or clay or a composite of these and other materials that build up at the entrances of the subterranean dwellings of ant colonies as they are excavated. A colony is built and maintained by legions of worker ants, who carry tiny bits of dirt and/or vegetation in their mandibles and deposit them near the exit of the colony. They normally deposit the dirt or vegetation at the top of the hill to prevent it from sliding back into the colony, but in some species they actively sculpt the materials into specific shapes, and may create nest chambers within the mound.

Note that in some areas of the world including English-speaking countries of Africa, in common speech the term ant-hill (also written as "anthill") refers to a termite mound.

Prohibition of tampering with ant colonies in Switzerland

For ecological reasons Swiss law prohibits killing forest ants or tampering with forest ant colonies since 1966.^[4]

See also

Wikimedia Commons has media related to:

Ant hill

• Nuno sa punso, a Filipino superstition about ant hills.
• Ant colony optimization, a technique in computer science inspired by ant colonies

External links

Journal of Insect Science: The nest architecture of the Florida harvester ant

Ant Hill Wood, a site about ants

References

1. ^ ^{a b} Tatiana Giraud, Jes S. Pedersen, and Laurent Kelle. Evolution of supercolonies: The Argentine ants of southern Europe. The National Academy of Sciences, 2002.
2. ^ Higashi, S. and K. Yamauchi. Influence of a Supercolonial Ant Formica (Formica) yessensis Forel on the Distribution of Other Ants in Ishikari Coast. Japanese Journal of Ecology, No. 29, 257-264, 1997.
3. ^ Super ant colony hits Australia. BBC News, 2004.
4. ^ Parc jurassien vaudois - Les Fourmis des bois