Diatoms are what make up diatomaceous earth and they are tiny bacteria that secrete a glass "skeleton". they use the "skeletons" from dead diatoms because, as Pet Lady said the sharp skeletons will cut the exoskeleton of spiders, ants, etc. and can damage the bodies of snails/slugs. I wouldn't recommend using it too close to your chameleon, but the water trick works well, that is what I do.