-they breath through the skin as they lack lungs.
-sizes can vary, some can be less than a half inch long and some over 10 feet.
-earthworms are both male and female producing both sperm and eggs.
Mitcham. Earthworm Dissection Lab.
"Earthworm." Wikipedia. Wikimedia Foundation, 04 Aug. 2014. Web. 09 Apr. 2014.
"10 Interesting Facts About Earthworms." EcoWatch. N.p.