Eggs that come from earthworms are wrapped in a protective cocoon. The eggs are sequestered in the ground for protection. Earthworms are able to hatch in 14 days in warm weather but take up to 60 days to hatch in cold weather. The average lifespan of a worm is four to eight years.
Worms are able to live as long as 10 years, depending on how well they are cared for. During the early stages of life, young worms are born without reproductive organs, but they are able to begin mating at 12 months of age. A ring of slime, known as the clitellum, forms around their reproductive area at 28 days old. The worms use this area to exchange sperm during the mating process.
Even though earthworms are born with male and female organs, they still need to mate with another earthworm for reproduction. Two earthworms wrap together and form an enclosure comprised of mucus that gives them room to exchange sperm. Fertilization then occurs in both of their bodies. Once the fertilization process is over, the worms expel the eggs. The cocoons form around the clitellum and hold anywhere from one to five worms. The cocoons are also able to protect the eggs until environmental conditions are suitable for the eggs to hatch.