It turns out that humans aren't the only animals that occasionally need a little help in the bedroom. According to the New York Times, researchers have discovered wild chimpanzees spicing up their love lives by creating sex toys. That's right: sex toys.

When Jane Goodall originally discovered toolmaking in chimpanzees back in 1960, the finding rocked the human world. No longer could humans draw a firm line between themselves and other animals based upon their use of tools. Now with this new discovery, it looks as though toolmaking rocks the chimp world, too.

So what exactly is the tool? Are chimps using vines for bondage? Strap-on branches? Does it involve bananas?

Well, no. It's something more subtle than that. The tool, explains University of Cambridge primatologist William C. McGrew, is a leaf. "The male will pluck a leaf, or a set of leaves, and sit so the female can see him. He spreads his legs so the female sees the erection, and he tears the leaf bit by bit down the midvein of the leaf, dropping the pieces as he detaches them. Sometimes he’ll do half a dozen leaves until she notices." 

It may seem like a crude, creepy version of "she loves me, she loves me not," but according to McGrew, the sound of a raspy leaf is, for a chimpanzee, more like the equivalent of a Marvin Gaye song. Or at least, it's enough to grab her attention and advertise his advances.

"Presumably she sees the erection and puts two and two together, and if she’s interested, she’ll typically approach and present her back side, and then they’ll mate," said McGrew.

So far, raspy leaf fetishes have only been witnessed among a single colony of chimps in Tanzania, so the unusual behavior is as much an indication of cultural evolution in chimpanzee society as it is an example of tool use.

Interestingly, the discovery may even help shed light on the long baffling, unexplained evolution of the human teenage phenomenon known as "cruising", or driving around town with car speakers blaring. Young human males may feel vindicated knowing that a similarly obnoxious tactic appears to actually work for chimpanzee males.

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