An earthworm can grow only so long. A well-fed adult will depend on what kind of worm it is, how many segments it has, how old it is and how well fed it is. An Lumbricus terrestris will be from 90-300 millimeters long. A worm has no arms, legs or eyes. There are approximately 2,700 different kinds of earthworms.
Worms live where there is food, moisture, oxygen and a favorable temperature.
If they don't have these things, they go somewhere else. In one acre of land, there can be more than a million earthworms. The largest earthworm ever found was in South Africa and measured 22 feet from its nose to the tip of its tail. Worms tunnel deeply in the soil and bring subsoil closer to the surface mixing it with the topsoil. Slime, a secretion of earthworms, contains nitrogen.