Earthworms are all in the lumbricus genus, which makes the first part of this animal's scientific name; the second part, or species name, varies. For example, according to National Geographic, the common earthworm is lumbricus terrestris, while according to the Fairfax County Public School system, the red earthworm is known as lumbricus rubellus.
Earthworms all appear roughly the same, but there are different species within the genus. The full scientific classification of earthworms starts with the animal kingdom and the Annelid phylum followed by class oligochaeta, order opisthopora, family lumbricidae, genus lumbricus and species terrestris (common earthworm, or nightcrawler) or rubellus (red earthworm). These herbivorous invertebrates can be found in soils throughout the northern hemisphere.