Diatomaceous Earth is a pesticide made from silica; which is fossilized remains of tiny aquatic organisms called diatoms.  They accumulate in sediments from rivers, streams, lakes and oceans.  When dusted on plants it causes insects to dry out and die.  Use on slugs, bed bugs, fleas, ants, cockroaches, centipedes, millipedes, caterpillars, beetles and more.  Available in a variety of sizes.  *Always read and follow label directions.