Non-selective contact killer, DE is the fossilized remains of single-celled creatures called diatoms. Each fossil has sharp edges that irritate and lacerate soft-bodied insects. The DE material abrades the exoskeleton of insects, causing dehydration and death. Effective on almost all crawling insects. Insects cannot become immune and will die within 48 hours of contact. Safe around children, pets and wildlife. Long lasting, odorless, non-staining.