HomeDepot.com, Walmart.com, Amazon.com and DiatomaceousEarth.com sell diatomaceous earth products online. Diatomaceous earth is used as a natural insect repellent; it wears down insects' exoskeletons and dehydrates bugs organically.
Diatomaceous earth is an amorphous silica, a naturally occurring, loose chalk-like substance composed of accumulated fossilized diatoms that form silica deposits in old freshwater lake beds. Diatomaceous earth can be used to combat many insect, including bedbugs, cockroaches, fleas and ticks. Diatomaceous earth has sharp edges that cut open insects and absorbs the oils and fat from their cuticles. The U.S. Food and Drug Administration recognizes diatomaceous earth as a generally safe substance.