Killing fire ants can be accomplished by a two-step method. The first step involves applying a commercially available bait to the area once or twice a year, which kills 80 to 90 percent of the ants. The bait should contain ingredients that affect the fire ant's nervous or digestive system, metabolism, reproduction or growth. The second step is to treat individual mounds with contact insecticides as they appear.
Baits must be returned to the colony and ingested by the queen to completely eradicate the ants. In large areas, they can be applied with a spreader. Some baits work in three to 10 days, while others may take as long as three weeks. The best time to apply bait is when the ants are actively foraging for food. The timing can be tested by putting out a small amount of bait. If it is gone within an hour, the bait can be set.
Fire ants can be responsible for injury or death of livestock, wildlife, domestic animals and humans. Control of their numbers requires vigilance, since new fire ants often move in from untreated areas.
Insecticides are formulated as dusts, granules, liquid drenches or baits. Most require water to activate. Some are more effective than others, varying in how quickly they kill the fire ants and how long they remain in the environment. A few are available for use only by professionals.