ANT (O. Eng. _aémete_, from Teutonic a, privative, and _maitan_, cut or bite off, i.e. "the biter off"; _aémete_ in Middle English became differentiated in dialect use to _amete_, then _amte_, and so _ant_, and also to _emete_, whence the synonym "emmet," now only used provincially, "ant" being the general literary form). The fact that the name of the ant has come down in English from a thousand years ago shows that this class of insects impressed the old inhabitants of England as they impressed the Hebrews and Greeks. The social instincts and industrious habits of ants have always made them favourite objects of study, and a vast amount of literature has accumulated on the subject of their structure and their modes of life.
_Characters._--An ant is easily recognized both by the casual observer and by the student of insects. Ants form a distinct and natural family (_Formicidae_) of the great order _Hymenoptera_, to which bees, wasps and sawflies also belong. The insects of this order have mandibles adapted for biting, and two pairs of membranous wings are usually present; the first abdominal segment (propodeum) becomes closely associated with the fore-body (thorax), of which it appears to form a part. In all ants the second (apparently the first) abdominal segment is very markedly constricted at its front and hind edges, so that it forms a "node" at the base of the hind-body (fig. 1), and in many ants the third abdominal segment is similarly "nodular" in form (fig. 3, _b, c._). It is this peculiar "waist" that catches the eye of the observer, and makes the insects so easy of recognition. Another conspicuous and well-known feature of ants is the wingless condition of the "workers," as the specialized females, with undeveloped ovaries, which form the largest proportion of the population of ant-communities, are called. Such "workers" are essential to the formation of a social community of Hymenoptera, and their wingless condition among the ants shows that their specialization has been carried further in this family than among the wasps and bees. Further, while among wasps and bees we find some solitary and some social genera, the ants as a family are social, though some aberrant species are dependent on the workers of other ants. It is interesting and suggestive that in a few families of digging Hymenoptera (such as the _Mutillidae_), allied to the ants, the females are wingless. The perfect female or "queen" ants (figs. 1, 1, 3, a) often cast their wings (fig. 3, b) after the nuptial flight; in a few species the females, and in still fewer the males, never develop wings. (For the so-called "white ants," which belong to an order far removed from the _Hymenoptera_, see TERMITE.)