Overview of the earthworm:
Earthworms belong to the order Oligochaeta and can grow anywhere from millimeters to some that over 2 and 3 feet long, the smaller earthworms that a only inches in length are the worms that are more commonly found.
Although it is not commonly thought of Earthworms do have a head and a mouth. The Head of the worm is found at the anterior end and the mouth at the same location. The worm also has male and female openings and receptacle openings. The Posterior end of the worm is the tail where the anus is found. Earthworms do not have limbs such as arms and do not have any eye balls.
If an earthworms loses a part of its body it can regrow it back to nearly original condition. Earthworms have the ability to regenerate parts of its body when necessary, for example if the worm loses a tail the tail can regrow back to the worm.
Earthworms eat mostly organic items out of the earth they do have certain foods that are preferred including dead leaves that have fallen off trees. The worms do have mouths but no teeth, once the worm ingests a bit of organic food it will pass through the body and out again.
The worm does not have lungs. It will breathe through the skin, so if the skin dries out the worm will die.