What Do Garden Worms Eat?

Worm Digestion

Worms have tiny, virtually invisible mouths, and no teeth. Instead, worms have a gizzard, much like that found in chickens. When they eat, they must consume soil along with their food. Tiny bits of sand and other grit are diverted into the worm's gizzard, where they grind against one another as well as any food the worm swallows. The resulting particles are combined with the worm's gastric juices to enable the worm to digest the food.

Garden worms eat almost any organic matter they encounter in the soil. This includes leaf litter, decaying matter, both plant and animal, plant residue and the soil itself. As they eat, the worms typically consume and digest microscopic organisms that are found in the soil and on decaying material. These organisms include nematodes, living protozoa, fungi, bacteria, and many other microorganisms that are present in the soil.

As worms eat, they excrete their feces, called castings, either into or on top of the soil. These castings contain many essential plant nutrients which have been transformed from a form not accessible to plants into a rich, highly beneficial compost that is immediately usable by plants. During the process of digestion, the worm's gut also adds beneficial microbes and extra nitrogen to the waste before expelling the castings. Worm castings are known to be an excellent source of nutrients for plants.

Worms are classified into three main categories, based on how deep in the soil they live and feed. The epigeic worms are those that live on or near the surface of the soil, surviving on any loose litter and surface soil they find. Right below them live the endogeic species, worms that eat mostly organic matter that has already worked its way into the soil below the surface. The deepest burrowing worms are the anecic worms. These may tunnel down as much as 6 to 10 feet into the soil. They come up to the surface to find food and pull it down into their tunnels before they eat it.