Most people know that insecticides kill insects.
However, the way in which these chemicals work is a mystery to most of us. How an insecticide works is called its mode of action. A complete understanding of the mode of action of an insecticide requires knowledge of how it affects a specific target site within an organism. The target site is usually a critical protein or enzyme in the insect, but some insecticides affect broader targets. For example, silica aerogels affect the entire lipid layer on the insect cuticle.