Black Jack 661 8oz Bed Bug Powder Insecticide, Kills Bedbugs And Crawling Insects Powder, specially designed to control crawling insects ideal for apartments, homes, hotels, schools, factories, mobile homes and more. This powder is long lasting and effective when kept dry. This powder maybe used for other insects like spiders, ants, flies, crickets, silverfish, slugs, beetles, fleas, and more. This powder kills insects by abrasively removing and breaking down the oily protective membrane which covers the insects body, legs, and other moving parts. Death results from dehydration, because it absorbs up to 50 percent of the insects fluids. An insect's body is approximately 65 percent water and when as little as 30 percent dehydration occurs the insect will die.