Worms, millipedes, and termites are three classic examples of insects that eat decaying organic matter. This falls under the category of decomposition, which is one of the main ecological processes that occur in nature. So yes, worms are decomposers.
No, worms do not have legs. But that doesn’t mean that they lack the ability to move. Through their bristles, earthworms can sense the thin layer of soft soil beneath the top layer of soil, and then use a combination of two muscle groups to propel themselves forward and ensure their safety as they wriggle through the underground.
Earthworms can be found almost anywhere. They are often found near water, mud or moist areas. Spring and fall are the best places to look for worms due to the soil conditions and temperatures. Try looking under rocks or areas that may be moist underneath.