Just like humans, chimpanzees use many methods of communication within their group. They are capable of expressing a wide-range of emotions using postures, gestures, and facial expressions. But if you’ve ever seen chimps at the zoo, you’ve probably seen them do something that humans most definitely do not do, which is to throw their poop – sometimes right at Grandma. The video of a chimp hitting an unsuspecting visitor to the zoo with its poop – bullseye! – probably made you laugh. But did it also make you wonder why chimps throw their feces in the first place?

In their natural habitat, when chimpanzees become angry, they often stand up, wave their arms, and throw branches or rocks – anything nearby that they can get their hands on. When chimps are removed from the wild and kept in captivity, they experience stress and agitation, which can cause them to react in the same way – by throwing things. Captive chimpanzees are deprived of the diverse objects they would find in nature, and the most readily available projectile is feces. Since they also tend to get a pretty strong reaction from people when they do throw it, their behaviour is reinforced and likely to be repeated, which explains the abundance of YouTube videos on this subject.

But if you’ve seen the dramatic escape scene in the movie, War for the Planet of the Apes, you might be wondering if there is more to this poop-throwing thing than simply anger and agitation. As it turns out, throwing can be seen as a form of communication among chimpanzees. The better they are at throwing and hitting their targets, the better they are at communicating with the others in their group. That’s because the chimps that are more likely to hit their targets showed heightened development in the motor cortex and left-brain hemispheres, the same side of the brain where communication processing occurs.

Basically, a well-coordinated chimp is a smart chimp.

Want to learn more about chimpanzee communication? Take a look at these 10 fun facts!