They nest underground below logs, stones, twigs, and shrubs, or in decayed wooden stumps, and are sometimes found living in termite mounds.

[10] An examination of R. varians showed that the superficial punctures of the gastric dorsum are coarser than usual, but these variants are found not only around the original collection site, but also throughout the southern regions of Australia.

[3] Under the present classification, the green-head ant is a member of the genus Rhytidoponera in the tribe Ectatommini, subfamily Ectatomminae.

[12] In general, green-head ants are monomorphic (occurs in a single form), measuring 5 to 7 mm (0.20 to 0.28 in) in length and varying in colour, ranging from green-blue to green-purple.

The head is emarginate (having a notched tip or edge) from its posterior view and also rugose, along with the thorax and node (a segment between the mesosoma and gaster); these body parts are covered with large confluent punctures.

[15] In contrast to the workers and queens, the funicular joints are shorter, the sculpture is denser on the head and thorax, the number of punctures is less than that of the other castes and the postpetiole is coarser.

In areas with more rainfall such as the New South Wales tablelands and Victorian savannahs, green-head ants are mostly green with purplish tints seen on the sides of the mesosoma.

[3] In the northern regions of New South Wales and Queensland, the alitrunk is reddish-violet, which shades into golden around the lower portions of the pleura.

They appear similar to sub-mature larvae, but the diameter differs, gradually decreasing from the fifth somite to the anterior end.

[20] It can be found in most areas of Western Australia but is less common in the north, and is present in the lower regions of the Northern Territory and east of Queensland.

[22] The habitat of the green-head ant varies, ranging from desert, heath, open forests, urban areas and woodland.

[13][20] These ants mainly live in moderate wooded or open areas, but they are abundant in lawns and gardens in cities.

[24] These nests are commonly found beneath grass roots or under logs, stones, twigs, or at the base of shrubs.

They are among the first insects to be seen foraging for food in areas where bushfires have occurred, and in some cases they return right after the embers have stopped smouldering.

A large expenditure of energy is required for a move: scouts must first find a suitable site, brood must be transported safely, and the colony is exposed to an increased risk of predation.

Like other temperate species, activity in colonies is greatly reduced during the colder months, which may be the reason there is a high proportion of nest abandonment during summer.

[12][13][19][27] The removal of the capitula (structure similar to an elaiosome) from Eurycnema goliath eggs reduces the chances of them being collected by green-head ants that carry them back into their nests.

[33] Green-head ants relocate almost half of the seeds they feed on approximately 60 to 78 centimetres (24 to 31 in) away from their nests in both unburned and burned habitats.

[38] The shorter foraging periods seen in smaller colonies results in these nests preserving energy and adopting behaviour that is less energetic.

As these ants are solitary foragers and rarely recruit other nestmates, the chance of a worker encountering others is improved by marking the ground with trail pheromones.

[40][41] In smaller colonies, age caste polyethism does not occur, with nursing and foraging initiated by both younger and older workers.

A predatory species such as the green-head ant may not be able to increase prey retrieval within its environment, even if there is a larger foraging force.

[45] In some nests of the green-head ant, some myrmecophilous insects such as the beetle Chlamydopsis longipes are sometimes seen living inside colonies.

[53][54][55] The ergatoid (wingless reproductive females) queens emerge from their nest and, like the workers, appress their head onto the ground and elevate their gaster, from which the intersegmental membrane at the back of the abdomen extends.

A queen is ready to mate when she turns her abdomen to the side, where the male will search for the genitalia with his copulatory apparatus (parts of the organ involved with copulation).

Observations show that most workers establishing their own colonies follow the typical behaviour of a Ponerine ant, laying eggs and rearing their larvae.

Such a case would mean that a new colony is probably formed by a number of workers leaving their parent nest, of which a few individuals are fertilised.

[49] Genetic patterns suggest that green-head ant workers mate with unrelated males from distant colonies.

[62] The increased intra-colony genetic variance resulting from low kinship is considered to provide a selective advantage in the form of an expanded pharmacological venom repertoire.

[12][19] An icepack or commercially available spray can be used to relieve the pain, but individuals experiencing an allergic reaction are normally taken to the hospital for treatment.