Fabre and her team searched scientific papers for mentions of other primates that engaged in mucophagy, or consuming boogers. They found 12 other species—including chimpanzees, macaques, and gorillas—that had been caught in the act. Since the behavior is so common, the scientists wondered if there could be some benefit to eating boogers.
“Mucus acts like a shield that protects the thin skin and blood vessels in the nostrils,” says Fabre. The sticky stuff also catches dust and pollen that can trigger allergies, as well as harmful pathogens, like bacteria and viruses. Some research hints that eating boogers full of grime and germs might boost the body’s disease-fighting immune system. But other research shows that nose picking can spread pathogens and make you sick. For now, it’s still a scientific mystery why many animals snack on their snot. “It might just be for its taste and crunchiness,” says Fabre.