Red Imported Fire Ant: Solenopsis invicta

The Red Imported Fire Ant, Solenopsis invicta, is an invasive ant under active Australian biosecurity control. The established Australian infestation is in south-east Queensland. [1] [5] WildGuardian’s MEDIUM label reflects the risk of painful, repeated stings and allergic reaction, as well as the need to avoid spreading a potential pest.

Do not disturb or treat a suspected nest yourself. Keep people and pets away, take a photo only if it can be done safely, and report the sighting through the official program. The National Fire Ant Eradication Program directs people to report suspected fire ants on 13 22 68, also written as 132 ANT. [2]

What to look for — from a safe distance

Workers vary in size within a single nest, generally from about 2–6 millimetres. They are copper-brown with a darker abdomen, but colour and size alone cannot confirm the species. [1] Many ordinary Australian ants can look similar.

A nest may be a dome-shaped mound or a flat patch of loose soil without an obvious entry hole. The official program gives a typical mound size of about 30 centimetres wide and 10 centimetres high, while noting that appearance varies. [1] Nests can occur in gardens, lawns, parks, farms, playgrounds, roadsides and driveways, as well as beneath logs, bricks or pavers and near waterbody edges. [1]

The feature with the greatest practical safety significance is behaviour. Disturbed colonies can swarm and sting repeatedly. [1] Do not touch ants or soil with bare hands, kick a mound, add bait or insecticide, or move material from the area.

Why reporting matters

Fire ants can build different colony structures and spread through both flight and colony budding. [3] The program’s response relies on early reports, specialist identification and coordinated treatment. A photo helps only if it can be taken without creating a sting risk; safety comes first. [2]

The Australian Government reported that a September 2026 detection at Strathfield was treated and destroyed, with no evidence then of spread beyond that site. [5] That event does not change the core message: check the current official reporting advice for your jurisdiction and report a suspected sighting instead of assuming it is an ordinary ant.

Reducing sting risk

Avoid contact with suspected ants and nests. Wear covered clothing, boots and gloves if you must be near an area for another essential reason, and keep children and pets back. [2] Never use a visual identification attempt as a reason to handle an ant or disturb soil.

After an ant sting, Healthdirect advises removing a visible stinger if possible, washing the area with soap and water and using a wrapped cold or ice pack for 15 minutes. [6] Do not scratch or pop any blister. Seek medical advice if symptoms worsen, if there is a large swelling, or if the sting is in the mouth or near an eye. [6]

For anaphylaxis, use an available prescribed adrenaline autoinjector, follow an ASCIA action plan and call 000. Warning signs include noisy breathing, a swollen tongue or throat, wheeze, persistent cough, voice change, dizziness or collapse. [6]

Frequently asked questions

Are all small red-brown ants fire ants?

No. Colour and size cannot confirm a fire ant. Report a suspected nest rather than trying to identify or treat it yourself. [1] [2]

Where are Red Imported Fire Ants established in Australia?

The active established infestation is in south-east Queensland. [5] Official programs investigate and treat detections elsewhere.

What should I do if I find a possible nest?

Keep clear, keep children and pets away, take a photo only if safe and report it through the official program on 13 22 68. [2]

What should I do after a sting?

Wash the area, apply a wrapped cold pack and watch for allergic-reaction symptoms. Use an adrenaline autoinjector and call 000 if anaphylaxis is suspected. [6]

References

1. [1] How to identify fire ants and nests — National Fire Ant Eradication Program
2. [2] How to report fire ants — National Fire Ant Eradication Program
3. [3] Lifecycle and reproduction — National Fire Ant Eradication Program
4. [4] Why fire ants are a problem — National Fire Ant Eradication Program
5. [5] Red imported fire ants detected in Strathfield — Australian Government
6. [6] Ant stings and bites — Healthdirect Australia