Terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers; SYN. angleworm, fishworm, fishing worm, wiggler, nightwalker, nightcrawler, dew worm, red worm.
Annelid worm of the class Oligochaeta. Earthworms are hermaphroditic and deposit their eggs in cocoons. They live by burrowing in the soil, feeding on the organic matter it contains. They are vital to the formation of humus, aerating the soil and leveling it by transferring earth from the deeper levels to the surface as castings.
Most North American earthworms belong to the genus Lumbricus. These are comparatively small, but some tropical forms reach over 1 m/3 ft in length. Megascolides australis, of Queensland, for instance, can be over 3 m/11 ft long.