Unfortunately, we can’t eradicate them completely, but we can help control them in our own yards and gardens.
Successfully controlling fire ants requires an understanding of basic fire ant biology. One thing is certain, we usually don’t know fire ants are there until we see the mound or feel the sting.
But fire ants do not require a mound for survival. In fact, during our hot summers and cool winters, you won’t find fire ants tunneling around in the mound — they go underground, several feet underground. For those that put out fire ant traps in the winter and summer months, this is one reason you may not have any luck. The fire ants simply are not foraging around at that time.
A fire ant mound begins with the mating flight. Once a female has mated — in air — she spreads the fire-ant wealth around, traveling many miles on air currents (or by catching a ride on your vehicle or anything else that travels, for that matter. Rain is another source of transportation. Red imported fire ants actually make rafts and float along in floods).
After landing, she will bury herself in the ground and lay eggs, starting a new underground colony. The mounds we see above ground are excavated tunnels — an extra room if you will. When it’s cool outside, you will most likely find the ant brood in the aboveground mound. In extremely hot weather, you will find the brood in the cool conditions below ground.
One of the reasons it’s so difficult to get rid of fire ants is because we commonly try to combat individual mounds. We treat the ground with chemicals, and it may kill some of the ants but remember, the majority of the colony is underground. So the mound will pop up again, maybe even a foot away. Once you understand their habitat, you see why this may not be the best way to combat fire ants.
The most recommended form of control is the two-step method. Step one: Once or twice a year distribute fresh fire ant bait (fresh bait is bait that’s properly stored and less than a year old). This alone will reduce colonies by 80-90 percent. The bait is picked up by foraging worker ants and taken back to the mound where other workers make it palatable for the entire colony. Fire ants forage when temperatures are between 65-90 degrees. To get the most out of your bait, leave a potato chip near the mound to see if the ants are foraging. Putting out bait when ants are not foraging, is a waste of bait.
Step two: treat any nuisance mounds that move in after the baiting with a contact insecticide.
You can find information about insecticides along with almost anything else you want to know about fire ants at www.extension.org/fire_ants. This is the nationwide web-based site on imported fire ant management.
And remember the label is law — always use pesticides according to the label.