Red imported fire ant: declared pest in Western Australia

Page last updated: Saturday, 21 October 2023 - 10:27am

Please note: This content may be out of date and is currently under review.


Red imported fire ants are small, varying from 2 to 6 millimetres long. They are reddish-brown in colour and look like many common native ants found around homes and gardens. As the name suggests, they have a fiery sting that blisters, followed by pustules which develop at the sites of the stings.

Red Imported Fire Ant size range [in a circle] – queen far right.Live red imported fire ants crawling on a piece of wood.

RIFA mounds

Fire ants build characteristic mounds of 'fluffy' friable soil that are low and squat, up to 40cm high and 50–75cm across. New mounds start as small piles of excavated soil and may be indistinguishable from those of many other ant species.

The mounds are built in open areas such as lawns and verges, sports grounds, golf courses and pasture paddocks and may number more than 100 per hectare. Mounds are unique in that there are no obvious ‘entry’ holes.

Red Imported Fire Ant mound with vegetation growing through it.

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080