The Royal Academy of Languages defines intelligence as the ability to understand, grasp concepts, or solve problems. For millennia, humans believed they stood alone in this gift, yet science has shown otherwise. Many animals display problem-solving skills, tool use, and a spectrum of emotions. Across numerous experiments, researchers have explored the cognitive and adaptive abilities of a wide range of species. A recent study reveals that chimpanzees (Pan troglodytes) use crushed insects to heal wounds.
Researchers from the Ozouga Chimpanzee Project in Germany and the University of Osnabrück observed a group of 45 chimpanzees over seven years in Loango National Park, Gabon. They documented that these animals apply crushed insects to wounds, and, notably, that they use the same remedy on the wounds of others, including peers who are not closely related. The behavior appears to function as a form of self-medication that extends to social care within the group.
The authors note that self-medication, defined as behaviors that help limit or counteract disease and parasitism, has been observed in numerous species, including bears, elephants, and starlings—and, of course, in great apes. Traditionally, studies of self-medication in non-human primates focused on ingesting plant parts or non-nutritive substances to suppress intestinal parasites. More recent work has also recorded topical applications of leaves or other materials, including arthropods, to skin or fur.
For example, chimpanzees have been observed swallowing or chewing leaves with antiparasitic properties to tackle gut parasites. Loango’s study marks the first known report of topical insect-based remedies applied to skin wounds.
healer chimpanzees
The study, published in Cell Current Biology, notes that prior observations of applying insects or insect parts to wounds in a member of the same group had not been documented. The report highlights the earliest known observations of chimpanzees taking a proactive role in healing, applying insects to their own wounds and to those of conspecifics.
The initial observation was made by Alessandra Mascaro, a project volunteer who filmed a female named Suzee tending her calf and placing something between her lips to apply to an open wound. Subsequent recordings showed the behavior recurring among other chimpanzees.
Researchers concluded that the objects brought from the air were likely flying insects. They then focused on filming injured chimpanzees in the group showing this behavior. The team is convinced that the insects used have anti-inflammatory or antiseptic properties, a hypothesis they continue to examine.
The authors aim to identify the precise insect species used, a challenging task because chimpanzees grind insects in their mouths as part of the process, making species confirmation difficult.
What stands out is that the chimpanzees did not only treat their own wounds; they also applied insects to the wounds of other individuals, sometimes distant from family ties. This behavior is described as pro-social, suggesting benefits to the broader group—a finding that challenges assumptions about chimpanzee social problem-solving and caregiving.
And baboons recognize written words
The discovery of word recognition in nonhuman primates came a decade earlier, when researchers reported that baboons (Papio sp.) can recognize written words. Studies from the University of Aix-Marseille in France showed that baboons, lacking human language, can master sign recognition—a foundational element of reading. The results, reported in Science, indicate that this ability is not exclusive to humans and may have predated the evolution of our species.
The key insight was that baboons distinguish meaningful from meaningless words by processing individual letters rather than using a holistic approach. Over roughly six weeks, several primates learned to differentiate dozens of meaningful words from thousands of meaningless strings. One subject, named Dan, identified hundreds of words during testing.
Researchers concluded that, in humans and baboons, recognizing words by letters mirrors how we recognize everyday objects by their parts. Additional studies with other primate species produced similar results: great apes can recognize written words. The capacity to process letter combinations is an early stage in reading acquisition, sometimes described as the initial phase of literacy learning.
Citation note: studies referenced are available in Cell Current Biology, with formal details provided in the publication record.