Earthworm

A common name referering to a segmented worm, Phylum Annelida?, class Oligochaeta?, order Opisthopora?. There are over 2,200 species known worldwide, existing everywhere but artic and arid climates. They range in size from 1 inch to 11 feet.

Earthworms live by burrowing underground in soils containing organic materials, which they help to decompose. The soil is ground up and the waste deposited behind the worm. This process aerates and mixes the soil, and is often considered greatly helpful by gardeners and farmers.

Earthworms are hermaphrodites, but cross fertilize, and lay cocoones giving birth to small but otherwise adult earthworms.

Various species of earthworms are used in Verniculture?, the practice of decomposing, or composting by the use of worms.

References

http://www.sarep.ucdavis.edu/worms/

http://www.encyclopedia.com/articles/03910.html