[3] Groups of bristles (called setae) on each segment of the worm move in and out to grip nearby surfaces as it stretches and contracts its muscles to push itself forward or backward.

(Lysenin is also toxic to organisms lacking sphingomyelin in their cell walls, including Bacillus megaterium, though the pathway is not understood).

[5][6][7] Vermicomposting septic systems have been used for decades and allow for decentralized on-site processing of blackwater using Eisenia fetida.

[11][12] When roughly handled, a redworm exudes a pungent liquid, thus the specific name fetida meaning "foul-smelling".

Molecular analyses have confirmed their identity as separate species, and breeding experiments have shown that they do produce hybrids.

[14] The mitochondrial genetic characteristics of the Irish population of E. fetida could be the result of reproductive isolation, so suggests that this sample may constitute an unrecognized species or subspecies of E.