Evolutionary biologist Allesandra Mascaro (Max Planck Institute) was the first to notice: chimpanzee mother Suzee caught an insect, crushed it with her lips, and then rubbed it on a wound on her son Sia. A week later, a doctoral student noticed the same behavior in another monkey. That got the researchers thinking.
They began observing the 45 chimpanzees in Loango National Park in West Africa, Gabonese, focusing mainly on injured monkeys. They did that for two years. Until the biologists had registered a total of 22 similar cases in which the chimpanzees used flies to treat the wounds of their conspecifics or their own. In 19 cases this involved personal care. Three monkeys rubbed the wound of a fellow species.
Since the researchers do not know which insects the chimpanzees use, it is still unclear whether the trick really works.
In any case, chimpanzees are not the first animals to self-medicate. For example, cats and dogs eat grass so they can vomit. And other great apes also eat leaves of plants that are not on the ‘menu’ during the week when they are battling parasites. Nevertheless, the chimpanzees are rather unique because they not only take care of themselves, but also other species.