Eisenia fetida. is the best choice. L. rubellus is invasive and is threatening North American Forests.
Quoting from:
Invasive Earthworms—A Threat to North American Forests
Plants & Gardens...
Individuals of the same species always live in the same habitat. If they start to preferentially live in different habitats then you have the beginnings of separate species.
Some insects will eat their partner after mating, such as the Preying Mantis and the Black Widow Spider. Other animals, such as lions, have been known to kill offspring from the same species if it is...
