Carpenter ants nest in wood, preferring moisture-laden, damp wood to dry wood. To adequately treat a carpenter ant infestation with products such as baits or insecticides, you must first determine the location of the nest and remove their source of food. The best carpenter ant insecticide is the product that cripples the ant colony and does not harm other creatures, especially you. A variety of carpenter ant pesticide treatments are available, or you might opt for a natural, environmentally friendly product such a boric acid or diatomaceous earth.
Ants are social insects, living and working in castes. Often, the only carpenter ants you will ever see are the worker ants who seek out food sources and new locations for satellite nests. Hiding within a labyrinth of tunnels lurk the egg-laying female carpenter ants, eggs, larvae and a multitude of worker ants. Never randomly douse ants with carpenter ant spray, because this might hinder eradication of the nest or make an infestation worse.
To locate the nest, create a simple carpenter ant bait: lay a strip of masking tape — with the sticky side down — where ants have been seen. Drop some diluted honey or jelly on the strip. Follow the ants to their nest after they feed. You might need to attempt this several times for good success. You must identify the location of the nest before applying any carpenter ant insecticide.
After you have discovered the nest, apply the insecticide at dusk, when the ants are likely to be in the nest. The most common and most effective chemical insecticides are carbaryl, diazinon, or chlorpyrifos, and they are available in sprays or as powders. Always follow the manufacturer's instructions when using pesticides. If necessary, you might also apply a thin stream of insecticide around the perimeter of your home to create a barrier.
Chemical pesticides such as chlorpyrifos and diazinon are organophosphates — toxic to birds, honeybees and the environment. Although any of these can be effective as a carpenter ant insecticide, these pesticides might be restricted in your municipality. A suitable non-toxic carpenter ant insecticide bait is boric acid mixed with honey and peanut butter. The ants, attracted to the bait, consume the boric acid, which slowly poisons their stomachs. Diatomaceous earth, a powdery natural product from fossilized, freshwater diatoms, cuts the exoskeletons of ants with its jagged edges, causing dehydration and death.
