Slowly, almost tenderly, the two lovers intertwine their bodies. After a long embrace they gently begin copulating. Then, a few seconds later, they stab each other in the head. If this doesn’t sound ...

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American Two-part barbed penises, a physical struggle ...

Courting is as unique to a species as dietary habits or dwelling. Some mating rituals seem almost aggressive, while others are dance-like and graceful. They can even be beautifully intimate, mimicking ...