Homes and Buildings
Fire ants from colonies close to homes and other buildings sometimes forage indoors for food and moisture, particularly during the hot, dry, summer months. Entire colonies occasionally nest in wall voids or rafters, or behind large appliances, sometimes moving into buildings during floods or drought. They are a nuisance and can threaten sleeping or invalid people and pets (see Texas A&M Agrilife Extension publication, Managing Household Ant Pests.
- It is best to control imported fire ants in the landscape, using one of the programs described for Home Lawns and Other Ornamental Turf Areas before they move into structures. If ants are entering the home from outdoor colonies, locate and treat mounds near the building. A contact insecticide with a long residual effect, such as fipronil or a pyrethroid, also can be applied as directed around the base of the structure as a barrier, but this treatment alone may not be effective at keeping ants out of the structure, particularly if overhanging vegetation or electrical wires allow ants to enter above the barrier treatment. It is important to caulk cracks and crevices, and screen weep holes to prevent ants from entering.
- If ants are foraging indoors, remove any food items on which the ants are feeding. Then use an insecticide bait product labeled specifically for fire ant control indoors. Examples are products containing abamectin or hydramethylnon or bait stations containing indoxacarb or other ingredients. Bait products not specifically registered for fire ant control may not be effective. Bait treatment alone may not control fire ants.
- Follow trails of foraging ants to colonies located indoors and treat them with contact insecticide dusts or sprays injected into the nest. Treating ant trails rarely eliminates an ant problem, and sometimes interferes with use of toxic baits. Some insecticides, such as chlorfenapyr (Phantom®) and imidacloprid (Premise®), which are available to professional applicators, are non-repellent to many ants and are compatible with the use of bait products. Most over-the-counter insect sprays, however, are repellent to ants and should not be used indoors when also using bait products.
Vacuum indoor ant trails and dispose of the vacuum bag immediately. A knee-hi stocking can be placed over the end of the vacuum hose prior to attachment placement to prevent ants from clinging to the hose or other vacuum parts. Tie off the stocking and place in soapy water or use another method to kill the ants prior to disposal. Treat the source colony or the point at which ants are seen entering a room using options described above.