Scientists have released stunning footage of chimpanzees using insects to treat wounds on themselves and others.
The video was captured by Alessandra Mascaro, a volunteer at the Loango Chimpanzee Project in the rainforest of Gabon, and marks the first recorded instance of this behavior.
Mascaro recorded the footage while following an endangered female central chimpanzee (Pan troglodytes troglodytes) named Suzee and her son, Sia. After inspecting a wound on Sia's foot, Suzee promptly snatched an insect from the underside of a leaf. The mother chimp then squeezed the insect in her mouth before applying the crushed bug to her child's wound.
Related: 8 human-like behaviors of primates
After discussing what they had found, Mascaro and her colleagues "realized that we had never seen such a behavior and that it had also never been documented before," she said.
Over the following 15 months, the researchers documented the behavior in 22 chimps from the group of roughly 45 individuals. Their observations revealed 19 instances where the chimps applied insects to their bodies, and two occasions where injured chimps were nursed by their fellows.
"An adult male, Littlegrey, had a deep open wound on his shin and Carol, an adult female, who had been grooming him, suddenly reached out to catch an insect," Lara Southern, an Ozouga volunteer, said in a statement. "What struck me most was that she handed it to Littlegrey, he applied it to his wound and subsequently Carol and two other adult chimpanzees also touched the wound and moved the insect on it. The three unrelated chimpanzees seemed to perform these behaviors solely for the benefit of their group member."
This is the first time that chimpanzees have been seen applying insects both to their wounds and to the wounds of others in their community. While animals have been spotted self-medicating before, those instances have mostly involved the animal simply consuming beneficial plants or insects, rather than performing a topical application to a wound.
The researchers don't yet know what insects the apes are snatching, but they think the chimps might be using some sort of winged insects as antibiotics, antivirals, or as a means to soothe pain and reduce inflammation. The wounds on chimpanzees can sometimes be several inches wide, and they are often inflicted during conflicts between groups or within the group itself.
In humans, the medicinal application of insects to wounds goes back as far as 1400 B.C., according to the researchers, and insects are still used for medicinal purposes today, ranging from honeybee products to treat inflammation to flesh-eating maggots to treat necrotic tissue.
The researchers argue that by applying insects to each other's wounds, the chimps are showing that prosocial behavior — or acting in the interests of others instead of just oneself — is not just a human trait.
"This is, for me, especially breathtaking because so many people doubt prosocial abilities in other animals," Simone Pika, a cognitive biologist at Osnabrück University In Germany, said in the statement. "Suddenly we have a species where we really see individuals caring for others."
Next, the researchers plan to identify the insects that the chimps are using and to figure out their potential pharmaceutical benefits. The researchers also want to tease out the social rules that govern this bug-sharing behavior.
"It is just fascinating to see that after decades of research on wild chimpanzees they still surprise us with unexpected new behaviours," Tobias Deschner, a primatologist at the Max Planck Institute for Evolutionary Anthropology in Germany, said in a statement.
The researchers published their findings Feb. 7 in the journal Current Biology.
Originally published on Live Science.