Aenictus

The most notable aspect of Aenictus is that they are "army ants". That is, they conduct raids using large numbers of workers, primarily attacking other ants, social wasps and termites, but also other arthropods. These raids occur both day and night, usually across the ground surface but occasionally also arboreally. During raids, many workers attack a single nest or small area, with several workers coordinating their efforts to carry large food items back to the nest or bivouac. They also have a nomadic life style, alternating between a migratory phase in which nests are temporary bivouacs in sheltered places above the ground and the stationary phase when semi-permanent underground nests are formed. During the nomadic phase bivouacs move regularly, sometimes more than once a day when larvae require large amounts of food. Individual nests usually contain up to several thousand workers, although nest fragments containing only a few hundred workers are often encountered. Queens are highly specialised and look less like workers than in most ant species. They have greatly enlarged gasters and are termed dichthadiform. New colonies are formed by the division of existing nests rather than by individual queens as in most ant species.



Worker of A. diclops from Queensland.



Worker of A. prolixus from the Northern Territory.



Worker of A. aratus from Queensland.

Identification
Workers of Aenictus may be separated from other Australian ants by their moderately small size (less than about 4 mm), lack of eyes, long slender bodies and long legs. They are superficially similar to some species in the subfamily Myrmicinae but differ in lacking the frontal lobes and in having the antennal sockets completely visible when viewed from the front (myrmicines have frontal lobes that are expanded towards the sides of the head and partly cover the antennal sockets). Some of the smaller, paler species are also similar to Leptanilla workers, but differ in being larger, in having only ten segments in the antennae rather than 12, and in laking a flexible promesonotal suture.

Males of Aenictus are often encountered more frequently than workers because they are attracted to lights. These males can be separated from those of other ants by the exposed antennal sockets, lack of a postpetiole and the smooth gaster which lacks a constriction between the first and second segments.

Distribution and Habitats
Australian distribution

Regional Species Lists

 * Australia

Keys to Species

 * Australia