Pavement ants are small ants about 1/8th inch long and dark brown to black in color. They are found throughout the eastern half of the U.S. and are a major pest in the upper Midwest. The name for this ant comes from its habit of nesting under sidewalks and driveways and piling dirt removed from the nest in a mound on top of the pavement.
In addition to nesting under sidewalks, pavement ants colonies can be found under other items lying on top of the ground, including stones, logs, boards, bricks and patio blocks. They may nest in open soil close to building foundations or under mulch in landscaped beds. Only rarely do the ants nest indoors in walls, under floors or in insulation.
Pavement ants will feed on a wide variety of different foods, though greasy and sweet materials are preferred. Worker ants may forage for food up to 30 feet from the colony and readily set up trails to and from food sources.
Control of pavement ants should begin with an attempt to locate the nest site. Ants entering buildings from outdoors can be discouraged by sealing as many cracks and gaps in exterior walls as possible. Also, correct poor foundation drainage and repair water leaks. A insecticide labeled for outdoor use against ants can be used outside to control individual ant hills near the house or to create a protective barrier to stop foragers from wandering into the house. Colonies living under sidewalks and slabs can be treated by sweeping granules into the cracks or by flooding the crack with insecticide solution. For more information about outdoor insecticides please see this article.
Pavement ant colonies living inside wall or floor voids can be treated with ready-to-use household insecticide sprays or dusts labeled for ant control. Inject a small amount of spray or sweep a small amount of dust into the nest area. For more information on indoor insecticides please see this article.
If the ant colony can not be found insecticide sprays can be used in the areas where foraging ants are seen. Also, ready to use ant baits (syrups or solid pellets in a small canister) can be placed in areas where ants are foraging, being careful to exclude contact with the bait by children and pets.