Earthworm
The body of an earthworm is made up of rings. The basic body plan of an earthworm is a tube. Earthworms have have a simple circulatory system. The earthworm breathes through its thin skin.
Earthworms are often seen after heavy rain because they need diffusion of gases across their skin .
Earthworms are good for soil fertility and growth of plants. Earthworms convert large pieces of dead leaves or other matters into rich humus. They also ingests any other small soil particles and excretes into a fine paste, adding minerals and plant nutrients into the soil.
Earthworms travel underground and keep the soil structure open, pumping air in and out of the soils.
Earthworms can range in size from only 1/25 inch long to up to 11 feet long.
Earthworms can be used fishing bait. So they are also called fishworm or angleworm. Earthworms are also important food for birds.
Earthworms lay eggs. Baby earthworms hatch after staying several weeks in the cocoon.
Earthworm cocoon picture