"It is a truth universally acknowledged that a hermaphroditic flatworm in possession of its own sperm, rarely runs short of sperm, and thus must be in want of another hermaphrodite of suitable quality to inseminate."

-Jane Austen, if she had studied flatworms

Sci is at Neurotic Physiology today, talking about how flatworms trade sperm. It turns out they are a species that gives as good as they get! Head over and check it out!