Earthworms have been used for literally thousands of years by gardeners for composting and improving the soil, as they enrich it with organic matter, and also aerate the soil. Earthworms are a natural presence in all healthy soils. But did you know that there are actually two different kinds of earthworms? What is the difference between an earthworm and a compost worm? The differences are relatively small, but very important to understand before you choose what kind of earthworm to introduce to your garden or compost bin.
Earthworms and compost worms are both similar-looking and have their uses but there is one major difference. Earthworms are 'True Worms' which means they are segmented and the segments grow back if they are cut off. They also have a direct digestive tract. Composting worms, although they are small, fast moving & can reproduce quickly, do not decompose soil like earthworms do because they do not have the same digestive tract or the segments. They will also die after a few days since composting worms eat only food scraps and don't eat soil.
Both of these worms are often confused with one another because of their similar appearance. Unlike compost worms, the worm that you find in the dirt is not ideal for your compost bin. Earthworms consume organic matter and are beneficial to soil as they eat decaying organic matter, which produces rich fertilizer in the form of castings, while also improving the moisture and drainage qualities of the soil. Compost worms on the other hand, are simply scavengers that feast on decaying plant material, and don't do the soil any good at all. Our composting worms reproduce quickly and efficiently when provided with a food source such as vegetable scraps.
Each species fulfills an important job in the natural environment which can be traced to its evolutionary roots. Earthworms and composting worms live in different habitats. Earthworms live in the soil, whereas composting worms live in the compost pile or bin. Also, each group has a different body design that enables each type of worm to fulfill its responsibilities better than another species.