# Red imported fire ant

*Solenopsis invicta*

**Identification confidence:** Identifiable with care — The mound structure plus aggressive swarming response is distinctive within the species' range.

## How to recognise it

- Reddish-brown head and thorax with a darker abdomen, and workers of clearly varying sizes within one colony.
- Two nodes on the waist and a two-segmented antennal club.
- Mounds are dome-shaped, up to about 45 cm across, with no single central opening — this absence of an obvious entrance hole is characteristic.
- Disturbing a mound produces immediate, coordinated swarming up vertical surfaces followed by near-simultaneous stinging.

## What it leaves behind

- Dome mounds in open sunny turf, appearing rapidly after rain.
- Stings producing a burning sensation followed within a day by a distinctive sterile white pustule.

## Why an infestation persists

Colonies relocate readily and can contain multiple queens. Stings are medically significant for people with hymenoptera allergy, and the characteristic pustule is a useful retrospective identifier.


## Where it occurs

Established across the Southeast and south-central states and parts of California; under federal and state quarantine in much of that range.

## What prevents it

- Keep play areas, patios, and walkways mown and inspected so mounds are found before someone stands on one.
- Reduce standing water and overwatering in turf, which concentrates colonies.
- Wear closed footwear in infested turf.

## Commonly confused with

- **Harvester ant** (*Pogonomyrmex spp.*) — Large at 5 to 10 mm, red to reddish-brown, with a conspicuous fringe of long hairs beneath the head forming a beard-like structure called a psammophore.
- **Pavement ant** (*Tetramorium immigrans*) — The head and thorax carry fine parallel grooves running front to back, visible under a hand lens as a striped or engraved texture.

**Verdict:** professional-recommended. Medically significant stings, quarantine regulations affecting soil and nursery stock movement, and colony relocation behaviour together put this beyond a reasonable homeowner response in most established-range settings.


Source: https://againstpest.shop/identify/ants/red-imported-fire-ant/