Order Hymenoptera (Ants, bees, wasps)

To get to know the habits of ants one must firstly be able to distinguish them from other insects and, secondly, be able to recognise which ant species is being dealt with. All ants belong to one group, know as a family, in this case the family Formicidae. Their nearest relatives are the various families of wasps, hornets and bees, and all these families together are classified in the Order Hymenoptera (membrane wings). There are sixty or seventy families in Order Hymenoptera in the world.

Ants are often confused with termites (or "white ants"). Termites not only form a different family but belong to a completely different order (the Isoptera) and are therefore not related to ants.

Family Formicidae (Ants)

A characteristic of most formicids is the possession of a metapleural gland. This gland produces phenylacetic acid, which fights against fungi and bacteria. It is made up of a pair of cell clusters which lead to two chambers in the rear of the ant's middle body. While the gland is the most diagnostic trait separating ants from other Hymenoptera, it is not universal among ants. Many arboreal species lack the metapleural gland (due perhaps to the drier, cleaner environment). Another trait that characterizes ants is their body structure. The ant head is connected by a thin neck to the thorax, which is then connected by a thin "waist" to the abdomen. While this is the general structure of many insects, ants are distinguished by the waist, which is pinched down posteriorly at its connection with the abdomen.

Native ants can be found everywhere in the world, excluding Antarctica, Iceland, Greenland, parts of Polynesia, and a few remote islands in the Atlantic and Indian Oceans. Within this vast range, 8,800 species have been documented, although upwards of 20,000 species have been estimated to exist. An exact figure would be exceedingly difficult to determine, since many species are difficult to differentiate. Ants can live in nearly every terrestrial habitat and environment, including deserts, beaches, in walls, and abandoned plumbing. Some species have even been known to survive underwater for as long as fourteen days by going into an anesthetized state, in which oxygen intake decreases to twenty times below the need of the ant when asleep.

Hymenoptera:
http://www.ucmp.berkeley.edu/arthropoda/uniramia/hymenoptera.html