Green-headed ants have a broad-ranging diet, but they generally feed on animal material both as scavengers and predators. They move quickly while foraging, which generally occurs during the day, on the ground and among vegetation. They are able to colonise disturbed areas quickly and have become common in urban areas. These ants are one of the first insects to forage after bush fires and are sometimes found as soon as the embers have stopped smouldering.

Unlike many ants, rain presents no problem to Green-head Ants, as long as it is only a light shower in continued sunshine. In overcast, cloudy conditions these ants return to their nests, which are usually in soil, under twigs or wood and often at the base of shrubs.

Greenhead ant nests are usually found on lawns, in gardens, around pathways under logs and rocks particularly in urban and suburban areas. These ants are seldom found nesting inside houses. They prefer animal and vegetative derived protein as a food source.

The green-headed ant is an infamous nuisance for suburban and urban dwellers in Australia. The ants generally build their nests underground beneath most types of grasses and often go unnoticed until someone, or sometimes some animal, is bitten. The actual ant's bite itself is often unnoticeable, however the venom that the ant injects via a sting, in its abdomen, initiates a sharp burning sensation beginning seconds after the sting and lasting up until any time from five minutes to as long as two hours or, with some subspecies, up to a day. The venom is generally harmless but if a large number of stings are received at once the overwhelming amount of venom injected into the body can sometimes render a small child physically ill for a few hours.

Some photos and information are provided by Bayer.