Fire Ant Infestation in a Garden

Fire ant nest (Tyabji via Wikimedia Commons, CC BY-SA 3.0)

Fire ants are small but aggressive pests that can quickly take over a garden. They can create mounds of dirt, which can damage plant roots and make it difficult for plants to grow properly. In addition, fire ants can bite and sting people and pets, causing red, painful welts and itching.


  • Visible mounds of dirt that can reach up to 18 inches in height and diameter
  • Ants actively crawling on plants and surrounding areas, including paths and sidewalks
  • Abnormal growth patterns in plants, such as yellowing leaves, stunted growth, or wilting
  • Ant bites and stings resulting in raised, red welts on skin and itching or burning sensations
  • Large numbers of ants appearing suddenly, seemingly out of nowhere
  • Ants quickly swarming and attacking when the nest is disturbed
  • Presence of winged reproductive ants (male and female swarmers) during mating season.

What is a Fire Ant

  • Small, reddish-brown ant, about 1/8 to 1/4 inch long
  • Has a two-segment waist and two bent antennae
  • May have a stinger at the end of its abdomen, which it uses for defense
  • Typically found in large groups, working together to gather food and build mounds
  • Has three pairs of legs, each with spines or hooks for climbing
  • Has large mandibles used for biting and tearing food
  • Has two large compound eyes and three simple eyes on the head
  • Worker ants can be either male or female and perform different tasks within the colony.

Treating a Fire Ant Infestation

It may be necessary to use multiple methods to effectively treat a fire ant infestation in a garden. For example, using a combination of chemical treatment and baiting can provide quicker results compared to just using one method alone. It is also important to continue monitoring the garden and reapplying treatments as needed to prevent re-infestation.

Chemical Treatment

  • Using insecticide sprays or dusts specifically labeled for fire ant control
  • Applying the product directly to the mounds and surrounding areas, targeting the queen and workers
  • Reapplying the product every 3-4 weeks or as directed on the label to ensure maximum effectiveness
  • Taking care to avoid contact with the skin and eyes and following all safety precautions listed on the label, including protective clothing and respiratory protection if needed
  • Paying attention to environmental factors, such as rain or wind, that may affect the efficacy of the treatment and adjust timing accordingly.


  • Using ant bait products specifically labeled for fire ant control
  • Placing bait stations near the mounds and surrounding areas, accessible to the ants but away from children, pets, and wildlife
  • Allowing the ants to carry the bait back to the colony to eliminate the queen and other workers
  • Monitoring the bait stations regularly and reapplying the bait every 3-4 weeks or as directed on the label for maximum effectiveness
  • Avoiding the use of other pesticides or treatments near the bait stations as this may affect the ants’ attraction to the bait.

Natural Solutions

  • Using a mixture of equal parts baking soda and powdered sugar to kill fire ants
  • Sprinkling the mixture near the mounds and surrounding areas, ensuring the ants come into contact with it
  • Reapplying the mixture every 3-4 weeks or as needed
  • Using nematodes, small worm-like parasites, to kill fire ants
  • Applying nematodes directly to the mounds and surrounding areas, following the instructions on the package carefully
  • Avoiding the use of other pesticides or treatments that may affect the nematodes’ ability to kill the ants.