🐜 Ants

Red imported fire ant

Solenopsis invicta

Mounds without a visible opening, and a sting you will not mistake.

Size
An eighth to a quarter inch (3–6 mm), with varied sizes in one colony
Colour
Reddish-brown head and body, darker abdomen
Risk
Medically significant
When
Mound-building spikes after spring and autumn rain
A red imported fire ant in profile: reddish-brown head and thorax, darker abdomen, and two small nodes in the waist.
One worker only. In a real mound the workers vary noticeably in size, and that variation is itself an identifier. AI-generated illustration · FreePestControlInspection.com

How to identify it

Work down these in order — the first one is usually enough on its own.

  • Workers within a single mound vary noticeably in size — unusual among common ants
  • Mounds are loose domed soil with no central entry hole; they enter through underground tunnels
  • Swarm aggressively and sting repeatedly when the mound is disturbed

What it gets mistaken for

Most people arrive at a pest name by ruling things out. These are the ones that genuinely look similar, and the detail that separates them.

Where you will find it

  • Open sunny lawn, especially after rain
  • Along driveways, sidewalk edges and fence lines
  • Around irrigation boxes and utility covers
  • Occasionally indoors during flooding or extended drought

Signs it is already there

You will nearly always see the evidence before you see the pest itself.

  • Domed mounds appearing quickly after rain
  • Clusters of stings after standing near a mound
  • Foraging trails leading toward a structure during dry spells

Medically significant. Can cause injury. Seek medical attention if you are bitten or stung.

Why it is harder to deal with than it looks

Pouring anything on a single mound usually just relocates it. Colonies move readily, and treating one mound in a yard that has twenty achieves very little.

What actually works

Whole-yard broadcast baiting at the right time of year, often followed by individual mound treatment where mounds sit near where people walk. Keep mounds away from play areas and anywhere someone might stand without looking.

Common questions

How do I tell a red imported fire ant from a odorous house ant?

Odorous house ants are uniformly small, dark and do not sting.

How do I tell a red imported fire ant from a carpenter ant?

Carpenter ants are larger, usually black, and nest in wood rather than soil mounds.

Where are red imported fire ant usually found in a home?s

Open sunny lawn, especially after rain Along driveways, sidewalk edges and fence lines Around irrigation boxes and utility covers.

Is a red imported fire ant dangerous?

Stings are painful and typically form a characteristic pustule. A minority of people have severe allergic reactions — if someone has difficulty breathing or swelling beyond the sting site, seek medical attention immediately.

Identification guidance only. Under Texas law, applying pest control treatments for hire requires a licence from the Texas Department of Agriculture. This page describes what a pest looks like — it is not a diagnosis of your property or a treatment recommendation for it.