It absorbs the waxy coating on the insect's body and causes death by dehydration. Silica gel products are often used by professional pest control operators to control cockroaches, silverfish, and other pests. Diatomaceous earth is the fossilized remains of tiny, one-celled organisms called diatoms. It kills insects by scratching their waxing outer covering and causing them to dehydrate. The diatomaceous earth sold for use in swimming pool filters is not suitable for pest control.
Diatomaceous earth is used to control cockroaches, ants, silverfish, and fleas.
Other Types of Less Toxic Insecticides Other types of less toxic insecticides include insecticidal soaps and insect growth regulators. Soaps penetrate the waxy covering on the insect s body and cause death by dehydration. They can be used indoors against such indoor plant pests as whiteflies and mealybugs. Insect growth regulators or IGRs are compounds that mimic insect hormones. They disrupt the insect s reproductive ability, but have no effect on humans.