Lumbricus terrestris is a large reddish worm native to Europe, but now also widely distributed elsewhere around the world (along with several other lumbricids), due to human introductions. In some areas where it has been introduced, some people consider it to be a serious pest species, since it is out-competing locally native worms.Through much of Europe it is the largest naturally occurring species of earthworm, typically reaching 20 - 25 cm in length when extended (though in parts of southern Europe there are native species which are much larger). It has an unusual habit of copulating on the surface at night, which makes it more visible than most other earthworms.
Although this is not the most abundant earthworm, not even in its native range, it is a very conspicuous and familiar earthworm species in garden and agricultural soils of the temperate zone, and is frequently seen on the surface, unlike most other earthworms. It is also used as the example earthworm for millions of biology students around the world, even in areas where the species does not exist.
The potential life span of Lumbricus terrestris is unknown, though it has lived up to the age of 6 years in captivity. The most widely accepted approximation is around 4-8 years in the wild.