Ants Nesting Indoors Buildings contain many favorable nesting sites for ants. Preferred sites include spaces behind walls, cabinets, light switches and receptacles, within window and door frames, and beneath floors. Most of these areas are hidden, making it extremely difficult to determine the precise location of the nest. The vicinity of a nest often can be determined, however, by tracing the ants' movement back to where they are entering and exiting the hidden location. After the ants have fed, they soon will head back to the nest.
Ants often nest in hollow areas such as behind walls or under the false bottom of cabinets.
Nests in these areas can be controlled by applying an insecticide dust into the suspected nest area. Drill and inject dust at least 3 feet on either side of the point where ants are disappearing to maximize your chances of contacting the nest. Insecticidal baits are another very effective means of eliminating ants nesting in homes. Baits are especially useful when the location of the nest cannot be determined, or the nest is inaccessible. Ant baits are convenient to use.