Diatomaceous earth is a remarkable, all-natural product made from tiny fossilized water plants. Diatomaceous Earth is a naturally occurring siliceous sedimentary mineral compound from microscopic skeletal remains of unicellular algae-like plants called diatoms.

Diatomaceous Earth will not harm warm-blooded animals or earthworms
Earthworm farmers use it to treat their worm beds for parasites, fungus gnat larva etc. Earth worms are structurally different from insects in that they can actually digest particles of DE. The particles are then eliminated in their castings.