There are almost thirty species of carpenter ants in the U.S. Fewer than ten species actually invade homes and cause problems for homeowners. Because carpenter ants often make their nests in wood, they can damage structural lumber in homes. Homeowners look for effective ways to control carpenter ants with minimum risk to the people and pets in the home. There are many natural products available for use against carpenter ants.
There are several products available that contain boric acid. This is a mineral that is refined so it can be used as an insecticide. One of the most common ways that boric acid is used against carpenter ants is in the form of dust. Small amounts of the dust are applied into the void spaces where carpenter ants make their nests. Other mineral dusts that can be used this way are silica gel and diatomaceous earth.
Since boric acid is toxic to insects, it is often used as the active ingredient in carpenter ant bait. The ant workers pick up the bait and take it to the nest. They share the bait with all of the other ants in the colony. As the ants swallow the bait, the boric acid has its toxic effect on them. If all of the ants get a share of the bait, the entire colony can be eliminated.
There are a number of insecticides that are extracted from plants or plant-related things. Citrus extracts, extracts from peppers, and plant essential oils are all used as ingredients in insecticides. There are a variety of these products, including aerosols, dusts, and liquids.
One of the most widely used botanical insecticides is pyrethrum. It is an extract from chrysanthemums. The pyrethrum is very repellent to insects and in a confined space it kills many insects. Insecticides that contain pyrethrum do not last very long after they are applied, so they are often used for flying insects.
Since carpenter ants make their nests inside of walls and other void spaces, pyrethrum can be an effective tool for controlling them. An aerosol that contains pyrethrum can be injected into the void where the ants have nested. In the confined space, many of the ants will be killed. This treatment can be combined with the dust injection as an effective treatment of carpenter ant nests.