During mating, two earthworms exchange sperm. Earthworms are hermaphrodites, meaning they have both male and female sex organs, and they produce both sperm and eggs.
During the mating process, two earthworms lay next to each other with their heads facing opposite directions. Each worm expels sperm into the other worm's male pore, called the spermatheca. The stored sperm is called the spermatozoa.
After the sperm has been exchanged, the worms produce a slimy film and begin to move forward. As they move out of the film, it picks up the eggs and passes them over the spermatozoa, allowing the eggs to become fertilized.
The film is then deposited into the soil, which is where the young worms will develop.