The most ubiquitous fire ant species in the southern US is the red imported fire ant (RIFA). Their mounds are most common in areas where there is high soil temperature. Grass in full sun or close to a hard surface such as cement, concrete or asphalt is likely to attract fire ant activity, especially in the spring. Fire ants may also create mounds at the base of ornamental plants.
If you have these mounds in or around your lawn, it is unlikely that extensive turfgrass damage will occur, but the mounds are unattractive and the fire ants will sting if disturbed. There are treatments to destroy these mounds and the ants within, but it can be difficult to ensure that all ants are killed. You may choose to treat individual mounds or use a broadcast treatment to cover larger areas. There are products (insecticide and bait) available to treat the mounds, but it is essential to make sure the mound is active when it is treated. If treatment isn’t sufficient, the queen, deep underground, may not be reached and the colony can be rebuilt.
If you have fire ants, consult with a professional (lawncare companies and extension agents are great resources) about the best way to control and eliminate this problem. Use all insecticide products according to label instructions for best and safest results.