Earthworms are long invertebrates that mostly live underground. They are decomposers that eat dead plant parts, such as leaves.

Earthworms drag dead plant parts into their underground holes, where they eat them. They do not like to venture above the ground during the daytime, because many bird species like to eat them. 

The earthworm in the picture moves quite quickly, even though it has no legs. Earthworms have no brains, but they use their sense of touch to feel their way around their environment.