; suborder Apocrita, family Formicidae)
Subfamily of tropical ants which have one or two petiolar segments, and in which the eyes are reduced or absent. Colonies contain several million individuals, produced by the single dichthadiiform queen. They are characterized by their legionary foraging activity, and nomadic behaviour (there are frequent changes in nest site). The bivouac (nest) is formed from the bodies of living ants, protecting the queen and brood within. There are about 200 species.
Subjects: Zoology and Animal Sciences.