If the nest cannot belocated, pay particular attention to places where ants enter the house or room. Dusts are best for this type of control because they can be puffed into wall voids that contain ant nests. Dusts provide the longest residual control in dry areas and can be tracked into the nest by foraging ants. Bait treatments are effective for control of many ant species if they eat the bait. They are enclosed in a childproof plastic tray and are broadly labeled for many ant species.
Boric acid is a good ingredient for ant baits and used in several commercial products.
Heat until boric acid completely dissolves. Dilute bait with an equal volume of water and with an eye-dropper, place in areas where ants feed, or in small lids where ants have access. Be sure to keep baits available to ants for 2 weeks. Keep bait mixture out of reach of children. This document is Fact Sheet ENY-203, a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.