Dorymyrmex insanus lives in colonies containing 2,000 to 3,000 individuals (4) in nests excavated in soil. The entrance to a Dorymyrmex insanus nest is a small hole in the ground, marked by a characteristic volcano-like mound of excavated earth measuring up to ten centimetres wide (3) (7).
Within each colony there are three classes or ‘castes’ of ants: males, workers and queens. As in most ant species, the virgin queens (winged females) mate with winged males, and afterwards, the males die while the queen sheds her wings and finds a suitable location to excavate a new nest. Here, the queen lays eggs and cares for the larvae and pupae until they reach maturity. These adults are typically all workers (sterile females) and assist the queen by caring for the next brood, foraging for food and expanding the nest. It is only once the colony is well established that winged virgin queens and males will be produced (8). Dorymyrmex insanus virgin queens and males spend winter in the nest before emerging in June (4), when they commence their search for a mate and a new nest site. A colony will persist as long as the queen is able to produce viable eggs (8).
Dorymyrmex insanus workers (the wingless, sterile females) are very active and opportunistic predators, feeding on a varied diet that includes vertebrate carcasses, termites, flies, beetles, and honeydew (3) (7). The workers form long trails that can be seen moving rapidly over and around objects as they search for food (3). Dorymyrmex insanus has a great tolerance for heat and can forage for food in temperatures that are too high for many other ant species (4).