Shipments of infested nursery stock and other agricultural products, natural mating flights and floating on flood waters have contributed to their spread. Expansion of these aggressive, venomous ants continues westward at a rate of about 120 miles per year, but the ultimate range of the fire ant is not known. Previously, it was thought that fire ants could not reproduce in temperatures below 10oF. New research has found fire ants can reproduce if the average minimum yearly temperature is greater than 0oF. Further expansion beyond this could occur if the fire ant becomes more cold-tolerant or if colder climates become warmer. Fire ants dwell in mounds that are easy to spot. When their mounds are disturbed, fire ants swarm to the surface and sting their victim.
Fire ants are a growing health hazard.
As many as 58 percent of a population living in infested areas are stung each year. Stings usually occur in the summer, most commonly in children and typically on the lower extremities. The fire ant gets its name from the immediate, intense burning and itching at the site of a sting. Almost everyone stung by a fire ant experiences some sort of a reaction to the venom, but 16 percent of people experience life-threatening reactions. Large local reactions may cause itching, swelling and redness on the entire limb.