Coastal Brown Ant

Pheidole megacephala

Coastal Brown Ants Coastal Brown Ants are dimorphic with small minor workers and large major workers which have massive heads. Loose soil thrown up around the nest entrances of the Coastal Brown Ant. Loose soil thrown up around the nest entrances of the Coastal Brown Ant.

The Coastal Brown Ant, sometimes also called the Big-headed Ant, is an introduced species that is common in urban and agricultural areas. It is the common small brown ant in Brisbane backyards. It occurs throughout the eastern seaboard and at Darwin, Perth and some inland towns.

It usually nests in the ground with nest entrances in the open or under rocks and logs or between pavers. Piles of loose soil are thrown up around nest entrances. It can also nest indoors, in crevices in brickwork, wall cavities, behind skirtings and architraves.

This species does not sting. It can be a nuisance pest in the garden and may enter houses to forage. It has a varied diet but prefers food of animal origin (protein and fats) to sweet foods. However, workers will tend sap-sucking insects for honeydew.

This ant is normally associated with human disturbance but has invaded native bushland in some areas. For example, it has infested monsoonal rainforest patches in the Northern Territory and some coral cays in the Great Barrier Reef. When this occurs the ant can build up to enormous populations and displace native ant species and affect other invertebrates.

Identification

This light brown species is dimorphic, with small minor workers (length 1.5-3.0) and larger major workers (length 3.5-4.5 mm) with massive darker heads. There are many native species of Pheidole that closely resemble the Coastal Brown Ant and require specialist identification to tell apart.

Queensland Museum's Find out about... is proudly supported by the Thyne Reid Foundation and the Tim Fairfax Family Foundation.