Diatomaceous Earth is composed of the fossilized exoskeletons of tiny organisms known as diatoms. These fossilized diatoms have very sharp edges allowing the diatomaceous earth to kill insects by lacerating their outer shells and dehydrating them.

When crawling insects come in contact with food grade diatomaceous earth it is much like crawling across shards of broken glass. The insects’ movement across the DE helps the razor sharp edges to lacerate its body.

In the pictures above (taken by Dean W. Blinn and J. Norman Grim) you are able to see just how diatomaceous earth works.

The image to the left shows food grade diatomaceous earth piercing the rear of a cockroach. In the image to the right, you are able to see DE particles lacerating an insect under extreme magnification.