When we talk about composting worms, we’re referring to Eisenia foetida. These are leaf litter worms, they live in the thin layer of decomposing material under the leaf litter but on top of the soil. Don’t confuse them with Earthworms who live in the first 6-12 inches of top soil or the mighty Nightcrawlers that build individual burrows up to 18 inches deep. They journey to the surface to feed each evening. In their natural habitat composting worms travel along the ground searching for food under the fallen leaves. When they find a rich source of nutrients like rotting fruit or manure, they will stay and often deposit egg sacks. As they slowly move they leave worm castings in their wake, creating soil. Because they don’t have the instinct to burrow under the frost line, they will die if frozen here in a Northern climate.