Australian ant  (Nothomyrmecia macrops)

This ant of ancient lineage is described as a ‘living fossil.’ It is perhaps the most ‘primitive’ ant still alive today (3). Ants are social insects, which typically live in colonies within nests comprising a single reproductive `queen’ and a force of non-reproductive `workers’, of whom the queen is the mother. Unlike the workers, virgin queens possess wings that are used only once for flight in a mating swarm, following which the wings are shed and the now fertilised queens begin colony foundation, typically alone (2). Seasonally, nests include immatures: eggs, larvae and pupae. Males, which are winged and develop from unfertilised eggs, are present only periodically each year, prior to the breeding season (2). The individual workers typically perform different roles; a characteristic known as `polyethism’ or `division of labour’ (2). Minimally, there are individuals specialised as foragers, working outside the nests, and others, which seldom leave the nests but perform in-nest activities, such as brood care. In advanced species these worker `castes’ may be physically differentiated, often including large-headed `soldiers’ (2). Nothomyrmecia workers are pale yellow in colour and have large eyes, distinctively long mandibles and a powerful sting (4); there is no soldier caste (2). Unusually, the queens have extremely reduced wings that are unlikely to be functional for flight (3). Virgin queens probably mate with flying males on tree trunks or the ground; the function of the reduced wings is not known (2).