Chimpanzees using insects to help treat other chimps' wounds may be proof that some animals can display emotions like empathy, which we usually attribute only to humans.
two chimpanzees grooming each other
Credit: Tom Brakefield / Getty

Many of us wouldn't think twice about helping someone apply a Band-Aid or spray a bit of antibiotic ointment on a scrape. But researchers studying chimpanzees in the west African nation of Gabon have observed chimps doing something similar: applying insects to treat their own wounds as well as using them to care for other chimps' injuries.

These findings add to the growing amount of research suggesting some animals exhibit prosocial behaviors associated with so-called "human emotions" like empathy, the ability to recognize and share others' feelings. They're treating others in a way that doesn't provide a direct benefit to themselves. (Something a few human internet users could think about doing more often.)

Simone Pika, co-author of the study and a cognitive biologist at the University of Osnabruck in Germany, told Agence France-Presse (AFP) their findings could be something that ends up in biology books.

The study began in 2019 when members of the Ozouga Chimpanzee Project, led by Pika and primatologist Tobias Deschner, received video of a female chimpanzee named Suzee catching an insect mid-flight, putting it in her mouth, appearing to squeeze it, and then applying it directly to a wound on her adolescent son's foot. Suzee then removed the insect from the wound and reapplied it twice.

A week later, a Ph.D. student observed Freddy, an adult male, doing something similar to his own wound.

Over the course of the next 15 months, the team recorded 19 instances of central chimpanzees in Gabon's Loango National Park using the insect treatment on themselves. The team also observed injured chimps being treated by other, sometimes unrelated, chimps using the same remedy.

Pika told the AFP the injured chimpanzees seemed to be happy to be tended to by other chimps in this way.

"It takes [a] lot of trust to put an insect in an open wound," she said. "They seem to understand that if you do this to me with this insect, then my wound gets better. It's amazing."

The researchers have yet to identify what species of insect the chimpanzees were using, but certain insects have established medicinal properties. Pika speculates the insects in question may contain anti-inflammatory compounds that generate a soothing effect.

Pika told that self-medication—where individuals use plant parts or non-nutritional substances to combat pathogens or parasites—has been observed across multiple animal species including insects, reptiles, birds, and mammals.

"For instance, our two closest living relatives, chimpanzees and bonobos, swallow leaves of plants with antihelmintic properties and chew bitter leaves that have chemical properties to kill intestinal parasites," she said.

Pika said some scientists still doubt animal species can perform prosocial behaviors like selflessly caring for others, but she hoped the chimpanzees' "clear" examples might convince some skeptics.