Female bed bugs have perfectly intact and straightforward reproductive tracts, but male bedbugs aren't into that. No, they opt instead for traumatic insemination, which is just as grisly as it sounds. The male's needle-like paramere--the bug equivalent of a penis--pierces the female's body, and he ejaculates directly into her abdominal cavity. For obvious reasons, traumatic insemination is not so great for the female bedbug; one estimate says it cuts their lifespan by a quarter.

Female bedbugs haven't exactly fought back, but they have, in a way, adapted to the trauma of bedbug sex. Off to one side of her abdomen is a small pale groove called the spermalege (photo). If the female is pierced in the spermalege, specialized tissue helps the wound heal and scar. Scientists have suggested the specialized organ evolved to prevent post-insemination infection, especially important since blood-sucking bedbugs don't live in the cleanest of habitats.