Fire ants invade compost piles and mulched flower beds seeking food, warmth and moisture. Nest sites may be difficult to locate precisely. When the exact location of a fire ant colony is unknown, treat the area of greatest ant activity with a fast-acting fire ant bait containing hydramethylnon, abamectin, indoxacarb or spinosad. If you want a "pesticide-free" compost pile, fire ant bait can be scattered around the base of the compost. Managing fire ants in areas surrounding the compost pile can reduce the chances of further problems. For example, see Management Options of Fire Ants for Home Lawns and Other Ornamental Turf.