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Fire ants: why treating the mounds you see isn't enough

Red imported fire ants build mounds in lawns across South Carolina. Treating each mound as it appears kills some colonies and misses the ones you haven't found yet, which is why the ants seem to move around the yard. Clemson recommends a two-step program: broadcast bait first, then treat problem mounds.

How do I know they're fire ants?

NC State Extension describes red imported fire ants as reddish to dark brown, with workers that vary in size from about an eighth to a quarter of an inch. NC State notes their mounds are usually dome-shaped in clay soil and more irregular in sandy soil.

Why do fire ants keep coming back?

Clemson explains that mound treatments only kill the colonies you treat. Colonies you didn't spot survive, and that leads people to believe the ants are just moving around. NC State adds that a drench sometimes misses part of a colony, and the survivors build new small mounds within 10 to 15 feet of the old one.

How does the two-step method work?

Step one is a broadcast bait across the whole yard at a time when the ants are foraging. Foraging ants carry the bait back to the colony, and it acts slowly enough that the queen eats it before the effects show. Step two, seven to ten days later, is a mound treatment on any mounds that are still a problem. Clemson says broadcast treatment is far more effective than treating mounds alone.

When should fire ant bait go down?

Clemson's newer guidance suggests baiting in late May or early June and again in late September or early October, when the soil surface is between about 70 and 85 degrees. In summer the ants forage mostly at night. Put a few greasy potato chips out and check them after 20 to 30 minutes: if ants are on them, they are foraging. Bait needs dry conditions, fresh product and patience, because results can take 2 to 12 weeks to show.

Where does do-it-yourself treatment go wrong?

• Treating only the mounds you can see.
• Baiting in the heat of a summer afternoon, when the ants aren't foraging, or right before rain or irrigation.
• Using an old, opened bag of bait. The oil in bait goes rancid, and Clemson advises buying only what you'll use in a season.
• Expecting results in a few days.

How does Spring Green treat fire ants?

Our fire ant service is one treatment a year, in January, with a guarantee of year-round control.

Last updated 2026-09-25. Spring Green is owned by Stockton Wells.