Today's interesting fact has to do with snakes.

Snakes have two hemipenes, or two half penis, that are stored inverted within the tail of the male.

One hemipenis is everted for reproduction by erectile tissue and one is used in mating.

They used to think that snakes (and lizards) alternated the one they use between matings.

But it turns out from recent observations that most snakes seem to be right handed.

In addition to having a forked tongue, the snakes hemipenes are also forked, and these forks are thought to help the male snake to grasp the female internally and aid in completing copulation.