What kind of ants do you have?
Nuisance ants are tiny and dark brown. Carpenter ants are big and black or black and red. Both eat small insects and bits of food and grease, and both seek moisture and nesting sites indoors – so, many strategies for preventing them are the same.
Keep ants out
Inside, use caulk or spackle to seal gaps between baseboards and floors, window frames and walls, and where under-counter plumbing enters the wall.
Outside, seal foundation cracks and holes around electrical, plumbing and cable lines. Use weather stripping to close gaps around doors and windows. This will help keep your home warmer, too.
Prune tree branches or shrubs away from the walls or roof of your house so ants can't use them as a bridge. Remove piles of wood or decaying stumps near your home's foundation so there are fewer places for ants to colonize. Check firewood carefully before bringing it inside.
Clean gutters and seal any leaks in siding, roof and plumbing so moisture does not attract ants or cause wood rot that invites infestations. Wooden parts of the house should not contact soil. Make sure sprinklers are not watering the house. For carpenter ants especially, repair any rotten or weather-damaged wood, and be sure that attic and crawl space ventilation is adequate.
What if they’re already inside?
Wash surfaces with soap and water, and make sure food is sealed in containers with tight lids.
Wipe ants up with a soapy rag. Soap kills ants and washes away the chemical markers they leave behind to guide other ants on the trail. If you have a lot of ants, you can vacuum them up and then remove the vacuum bag, seal it tightly in plastic and dispose of it in the trash.
If problems with nuisance ants persist, use bait stations. Look for ones with boric acid or some form of “tetraborate” as the only active ingredients, and keep them out of reach of children and pets.
Professional ant removal
Carpenter ants are difficult to deal with without the help of a professional. Ask questions and be wary if they suggest perimeter sprays – they are relatively ineffective and unsafe. Removing colonies is more effective.
If chemicals are needed, ask about less toxic options such as desiccants, boric acid and eugenol, instead of organophosphates, carbamates and pyrethrins.
Get a written proposal that includes what pests were found, what products will be used and what guarantees they have in case of potential problems.
Find more tips on nontoxic pest control