[S]cientists working with capuchin monkeys in South America had often seen the monkeys grabbing certain types of millipedes, crushing them and then massaging the dead insects into their fur. Sometimes it was a social event—four or five monkeys would share the same millipede, rubbing it all over themselves and then passing it to a friend. Afterwards, they started drooling and their eyes sometimes glazed over. Maybe, some of the scientists speculated, the millipedes were mildly psychoactive and the monkeys were getting high off of their secretions.
When a team of researchers actually analyzed the chemicals that the millipedes produced, though, they realized that the monkeys weren’t catching a buzz, but getting rid of one. The millipedes produced two chemicals, both compounds called benzoquinones, that happen to be excellent mosquito repellents. The monkeys were using the millipedes like bug spray.
via Mental Floss
