The uses of earthworms are divers. Earthworms are used for fish bait, composting, as a protein source for animal feed, and in producing pharmaceuticals (particularly in China).

Earthworms in soil provide abundant benefits in increasing water infiltration, soil structure, and nutrient cycling. While taken for granted over the years by many, it has been only recently that scientists, soil ecologists, horticulturists, educators, and waste managers have led the way in expanding our understanding of these remarkable creatures.

Within the past couple decades earthworms, particularly the species Eisenia foetida (redworm, red wiggler), have been found capable of transforming huge quantities of garbage into something akin to gold. Earthworm excreta, known as earthworm castings, are now known to contain plant growth regulators and other substances that make them nature's most remarkable form of bio-fertilizer and bio-pest control agent.