Earthworms are classified in the phylum Annelida or Annelids. Earthworm is a reddish brown terrestrial invertebrate that inhabits the upper layer of the moist soil. They are the main contributors to enriching and improving soil for plants, animals and even humans. During day time, they live in burrows made by boring and swallowing the soil. In the gardens, they can be traced by their faecal deposits known as worm castings.
The common earthworms are Pheretima and Lumbricus.