The Reproduction Cycle of Earthworms

Earthworms are rarely seen, but they are vital to the health of the soil they live in. These creatures spend most of their lives underground, feeding on soil and breaking it down. Since earthworms rarely come in contact with each other, they are hermaphroditic so that they can mate with any earthworm that they meet. Contrary to popular belief, one earthworm cannot reproduce alone. In fact, they have very specific needs to reproduce.

  1. Sexual Maturity

    • Earthworms become sexually mature when they are around two months old. When an earthworm is ready to mate, it develops a light ring, called a clitellum, behind its head. The clitellum contains both male and female reproductive organs.

    Conditions for Mating

    • In order to reproduce, earthworms must have the proper conditions. The temperature of the soil around them should be around 55 degrees F., which means that earthworms generally reproduce in the spring or fall. Earthworms prefer to mate after it has rained, so the soil is moist and it is easy for them to produce plenty of mucus.

    Finding Mates

    • Some earthworms search to find other earthworms to mate with. They find other worms by sensing the vibrations they make as they travel through the soil. Others wait in the doorways of their burrows for another earthworm in their group to come by.

    Mating and Fertilization

    • When two sexually mature earthworms meet, they move close together, head to tail, and simultaneously exchange sperm. Then, a tube made completely of mucus forms around each clitellum. When the tubes are dry, they fill with liquid and the worms squeeze out of them. As the worms' female parts move through the mucus tubes, the earthworms deposit eggs into them. As their male parts move through the mucus tubes, the earthworms deposit their partner's sperm. The eggs within the tubes are then fertilized by the sperm.

    Eggs and Young

    • After the worms go on their way, the ends of the tubes close, creating a safe capsule for the eggs. There are generally no more than five eggs in each cocoon. In approximately 60 days, the eggs develop and the young worms inside hatch out. They then consume the mucus tube in order to get their first nourishment. However, the young worms do not always hatch. In order for the young to survive, the surrounding soil needs to have enough bacteria. If it does not, the earthworms will not hatch at all. Earthworms that do hatch begin life as a very light color that darkens within a few days. If they survive long enough, they will become sexually mature adults by the time that they are two months old.