Kill carpenter ants by using boric acid, an odorless and non-staining compound available in dry powder or liquid form, writes Orkin. Puff the boric acid into cracks or crevices that carpenter ants use to navigate around the property. Combine liquid boric acid with a food attractant for best results.
In its powder form, boric acid adheres to an ant's legs; the ant ingests the powder as it grooms itself. Ants directly ingest the poison when in its liquid form.
The most efficient way of curbing an ant infestation is to destroy the colony, writes the University of Kentucky. Diluted honey dripped over masking tape can help a homeowner track a carpenter ant back to its colony. Because carpenter ants are more active at night, it is best to track them after dark. Eventually, a carpenter ant finds its way back to its colony or vanishes behind a wall or baseboard; treat this area with the boric acid.
Carpenter ants may establish multiple nests, warns the University of Kentucky. They begin with parent colonies that contain an egg-laying queen, then build multiple satellite colonies that contain worker ants. Carpenter ants inside a home may create a satellite colony in moist wood indoors that funnels to a parent colony in a tree stump or elsewhere.