Fresh water sourced, silica-rich food grade powder also known as fossil shell flour, diatomite and kieselgur. It is a naturally-occurring, soft, siliceous sedimentary rock that is easily crumbled into a fine powder. When insects come into contact with DE their waxy coated shells are damaged by microscopic, razor-sharp edges. Initially this causes decreased mobility and eventually the insect will perish due to dehydration. Apply a light dusting to desired area as a preventative or direct treatment. Works well in void spaces and anywhere that insects inhabit. The silica in diatomaceous earth is actually a primary ingredient in many of the over priced hair supplements at your local pharmacy. As well as being rich in silica Diatomaceous Earth (DE) is rich in over 11 essential trace minerals including calcium, magnesium, potassium, zinc and selenium.