Here is something snakes and lizards share that no other reptile has: the males have two reproductive organs instead of one. They are called hemipenes (HEM-ee-pee-neez), and a single one is a hemipenis. "Hemi" means half, so the name means each one is half of a pair. When not in use, the hemipenes sit inside the base of the tail, just behind the vent (the opening under the tail that a reptile uses for waste and for reproduction). They are stored inside-out, like a sock pushed into itself, and they turn right-side out when needed.
This lesson is part of Certified Junior Herpetologist. Enrollment is self-paced, with no deadline to finish (about 30 hours).
