As part of a series on the science of sex at New York's incredible World Science Festival, neuroscientist Jim Pfaus talked about how clitoral stimulation affects women's brains. And he notes that the same structures exist in rat brains — indicating that clitoral sexual response is probably an ancient development in animal brains, predating the development of humans by a long shot.

Also, Pfaus inadvertently explains a research job you probably didn't know existed: rat clitoris stimulator. That's right. Pfaus and his graduate students have to stimulate female rat clitorises with tiny paintbrushes.

You can watch more video from the World Science Festival here, and videos specifically from the series about sexuality here.