Wiggly Worms Small Animals, Big Changes. Do you know about earthworms? These small animals change the soil in big ways. Earthworm Bodies. An earthworm's body is shaped like one tube inside another. On the outside is a tube of muscle. On the inside is a tube that breaks down food. The body of an earthworm is made up of many parts. Each part is shaped like a ring and can bend and stretch. Earthworms move by stretching out their bodies and pulling themselves forward. Short, tough hairs on their bellies help them hold onto the ground. Slimy Worms! Earthworms are slimy. The slime helps keep earthworms cool and wet. It also helps earthworms slide through soil. After worms mate, a ball of slime forms. The slime dries into a cocoon. Baby worms come out of the cocoon. Earthworm Behavior. Earthworms build long tunnels underground. The tunnels protect worms from heat and sunlight. They also help earthworms hide from hungry animals. Earthworms are sometimes called night crawlers because they come out at night to feed. They use their mouths to pull dead leaves and plants into their tunnels. Earthworms Are Good for the Soil. Farmers love earthworms! When earthworms dig tunnels, they make space in the soil. The space helps plants get what they need to grow. Some people raise earthworms on worm farms. The earthworms eat food scraps, turning them into rich soil. Earthworm waste helps plants grow big and strong. Wanted: Earthworms! Farmers aren't the only ones who love earthworms. Moles, rats, and toads love juicy night crawlers. They love to eat them! Worms make good fishing bait because fish think earthworms are tasty, too. Earthworms are important food for these and other animals. Earthworms may be small, but they have a big job. Earthworms help plants grow!