University of Florida

Fire Ants

Fire ants are notorious for their painful, burning stings that result in pustules and intense itching, which can persist for up to 10 days. Infections may occur if pustules are broken. Some people have allergic reactions to fire ant stings, which can be severe. Besides humans, fire ants can sting pets, livestock, and wildlife.

Native to South America, fire ants are considered an invasive species in the United States. They are aggressive, reddish brown to black, and from one-eighth to one-quarter of an inch long.


Fire ants build large nests, usually in the form of visible dirt mounds, but also:

  • In rotting logs
  • Around trees and stumps
  • Under pavement and buildings
  • Indoors
  • Inside electrical equipment and utility housings (this can result in short circuits)

When their nests are disturbed, many fire ants will quickly run out of the mound and attack any intruder.


Fire ants are omnivorous feeders. They will eat:

  • Carbohydrates (e.g., fruits, sugars, and syrups)
  • Proteins (e.g., insects and meat)
  • Lipids (e.g., grease, lard, and oils from seeds)

Workers will forage for food more than 100 feet from the nest. They can forage during both the day and the night, generally when air temperatures are between 70° and 90°F. When a large food source is found, the ants recruit other workers to help take the food back to the colony.

Treatment Options

Imported fire ants have been the target of innumerable methods of control. Unfortunately, there are no control methods that will permanently eliminate fire ants from an area. Four strategies are currently being used to control fire ants:

  • Broadcast bait applications
  • Individual mound treatments
  • A combination of broadcast baiting and individual mound treatments
  • Barrier and spot treatments


In areas where both fire ant populations and native ants have been reduced or eliminated with insecticides, reinfestation by fire ants may be noticeable within a month after treatment. Fire ants reinfest these areas more rapidly than other ant species and can outcompete them. If fire ant control is not maintained, the subsequent reinfestation of an area may result in even greater fire ant populations than existed before the application of insecticides.


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