Bleep you like an animal

This is super funny. Apparently you can make female mice think they're males and try to hump everything in sight by removing their vomeronasal organs (either by genetic knockout or surgically).

Poor black mouse, the girl-on-top position doesn't work so well when you have four legs.

So sexual behaviour in mice is hardwired, but you can flip the switch:

Dulac thinks it makes total sense: "Instead of building a male brain and then a female brain, you build a mouse brain, and then there's a sensory switch that makes sure that the animal behaves appropriately according to its gender."

Let's not jump to any conclusions about the mutability or lack thereof of human gender, though:

It isn't clear how these findings might translate to other species. Many researchers think that the human vomeronasal organ is defunct, and the human TRPC2 gene is functionless.

"Different species use different sensory strategies to understand the world," says Dulac. She notes that whereas rodents use pheromones as an important trigger for sexual behaviour, primates and humans are more visual creatures.