Example of typical male (1), worker (2), and queen (3) ants. Many ants are fond of "honeydew" excreted by aphids. They "milk" the aphids by gently stroking the creatures' backs (4). Honeypot ants (5) found in some species, are fed so much sugary liquid by the workers that their abdomens swell grossly. They hang like storage tanks from the roof of a chamber of the nest, regurgitating the liquid food on demand.
An ant is a social insect of the family Formicidae of the order Hymenoptera, recognizable through the petiole or "waist" between abdomen and thorax. There are some 3,500 species of ant, each species containing three distinct castes: male, female, and worker.
Males can be found only at certain times of year: winged, they are not readmitted to the nest after the mating flight. The queen is likewise winged, but she rubs her wings off after mating; she may survive for as long as 15 years, still laying eggs fertilized during the original mating flight. The workers are sterile females, sometimes falling into two distinct size categories, the larger ones (soldiers) defending the nest and assisting with heavier work.
The most primitive ants (Poninae) may form nests with only a few individuals; nests of wood ants (Fornica rufa), however, may contain more than 100,000 individuals. Dorylinae, the so-called army ants, do not build nests at all but are nomadic, traveling in "armies" up to 150,000 strong: like Ponerinae (but unlike the more sophisticated species, which are vegetarian) they are carnivorous. Nesting ants welcome some insects, mainly beetles, to their nests, and often "farm" aphids for honeydew.