Worms are more powerful than the African elephant and more important to the economy than the cow. There can be a million or more earthworms in one acre of soil. Worms do not have teeth. Organic matter is ground up in a worm's gizzard. Redworms are surface-dwellers, preferring the top six inches of soil.
Nightcrawlers are soil-dwellers, and like to burrow several feet below the surface.
There are approximately 3,000 species of earthworms named and known to science. Earthworms are neither male, nor female, but both. Each worm can produce eggs and sperm. Worms have no eyes, but they are sensitive to light. Don't add too much and strew it like you do with sugar on your corn flakes.