10 Best Carpenter Ant Killers 2026 in the United States

The TERRO T300B Indoor Liquid Ant Killer with 12 bait stations is a highly effective solution for tackling indoor ant infestations. Its active ingredient, Borax, is well-known for its ant-killing properties. This liquid formulation ensures that ants are quickly attracted to the bait, which they then carry back to the colony, leading to a noticeable reduction in ant activity within a few days. This makes it an excellent choice for those dealing with a widespread ant problem indoors.

The Ortho Home Defense Insect Killer is a ready-to-use spray containing 0.05% bifenthrin, an active ingredient effective against ants, including carpenter ants. It comes in a liquid spray formulation and includes a battery-powered Comfort Wand, which simplifies application indoors and along outdoor perimeters. This makes it suitable for treating areas such as kitchens, bathrooms, doorways, patios, and foundations where ants commonly appear.

Spectracide Terminate Termite & Carpenter Ant Killer Concentrate is designed for outdoor use to protect your home from termites, carpenter ants, and other listed pests. It comes as a concentrated liquid that you mix with water before applying. This allows you to treat a large area—up to 16,000 square feet with one 32-ounce bottle—which is convenient if you have a sizable outdoor space like a porch, fence, or woodpile to protect. The product works by killing pests on contact and provides protection for up to 8 weeks, which means you don’t have to reapply very often. Many users find it effective at controlling carpenter ants and termites when applied around the foundation or other outdoor wooden areas. However, it is important to note that it is meant for localized control and outdoor use only, so it won’t treat termite infestations inside your home.