Advance 375A Ant Bait, Maxforce Carpenter Ant Bait Gel and Taurus SC are effective products for killing carpenter ants, according to Do It Yourself Pest Control. Alpine Ant & Termite Foam and D Fense Dust are also highly rated products.
Advance 375A Ant Bait exploits carpenter ants' dietary protein requirements. When the ants encounter the bait, they carry it back to the nest, eventually poisoning the queen and killing the entire colony. This product works well in conjunction with Maxforce Carpenter Ant Bait Gel, a sweet-tasting bait. These products are weather-resistant and work well in exposed outdoor locations.
Taurus SC effectively combats free-ranging carpenter ants. Applying this liquid insecticide four to six times per year prevents wandering ants from establishing new colonies in the treated area.