Science & Nature • Insect

Fire ant

Fire ant is a common name for several ant species in the genus Solenopsis, especially the red imported fire ant, Solenopsis invicta.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 27, 2026|2 min read| Fact-checked

Fire ant is a common name for several ant species in the genus Solenopsis, especially the red imported fire ant, Solenopsis invicta. These ants are known for their aggressive behaviour, large mound nests, and painful stings caused by venom. Fire ants are native to the Americas and have become invasive in parts of North America and elsewhere.

Classification and naming

Fire ants are ants in the genus Solenopsis, a group that includes many species. In everyday use, the name often refers specifically to the red imported fire ant, Solenopsis invicta.

Appearance and behaviour

Fire ants are usually reddish brown to dark brown and are known for swarming aggressively when their nest is disturbed. Their sting injects venom that can cause pain, itching, and blisters in humans.

Nests and colonies

Fire ants live in colonies that may include many workers and one or more queens, depending on the species and colony form. They build underground tunnel systems and visible mounds of soil or debris.

Distribution and invasiveness

Fire ants are native to the Americas, especially South America, but some species have spread widely beyond their native range. The red imported fire ant is established in parts of North America and has also been introduced to other regions.

Key facts

Fire ant refers to multiple species in the genus Solenopsis, not just one ant.
They are named for the burning sensation caused by their venomous sting.
Fire ant colonies can be very large and may contain hundreds of thousands of workers.
The red imported fire ant is a major invasive species in the southern United States and other regions.
Fire ants are native to the Americas and have become invasive in parts of North America and elsewhere.

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Canadian context

Fire ants are relevant to Canadian readers mainly as invasive-pest and biosecurity concerns, since Canadian pest-control companies and Canadian sources monitor their spread and identification, especially with trade and travel links to warmer regions.

Frequently asked questions

What are fire ants?

Fire ants are a group of ants in the genus Solenopsis, known for their aggressive defence and painful sting.

Are all fire ants the same species?

No. “Fire ant” is a common name for multiple Solenopsis species, though it often refers to Solenopsis invicta.

Why are they called fire ants?

They are called fire ants because their sting produces a burning sensation.

Where are fire ants native to?

Fire ants are native to the Americas, especially South America.

Do fire ants live in large colonies?

Yes. Their colonies can be very large, sometimes containing hundreds of thousands of workers.

Are fire ants dangerous?

Their stings are painful and can trigger allergic reactions in some people, so they are considered a public-health nuisance in affected areas.

References

Encyclopaedia Britannica — https://www.britannica.com/animal/fire-ant
Supports: Fire ants as a genus (Solenopsis) and their broad distribution
ScienceDirect Topics — https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/fire-ants
Supports: General biology, venom, and genus-level classification
U.S. National Park Service — https://www.nps.gov/fosm/learn/nature/fire-ants.htm
Supports: Scientific name Solenopsis invicta and order Hymenoptera
Orkin Canada — https://www.orkincanada.ca/pests/ants/fire-ants/
Supports: Native range, mound nesting, and Canadian pest-control relevance
Invasive Species Council of Australia — https://invasives.org.au/blog/8-facts-every-australian-should-know-about-fire-ants/
Supports: Native range, invasive spread, and ecological impact