The more we try to understand chimpanzees, one of our closest relatives, the more we find ourselves humbled by the richness and complexity of their lives — and of their intelligence. Today, on World Chimpanzee Day, we look back at some of the latest studies that reveal facets of these great apes’ long, powerful memories. Finding hidden ant nests Previous research has confirmed chimpanzees (Pan troglodytes) in the wild remember where their favorite fruit trees are, season after season. A recent study that monitored chimpanzees in Dindefelo Community Nature Reserve in Senegal has found chimps also remember locations of hidden underground ant nests for years. They repeatedly return to these sites, using their sight, smell, taste and touch to detect the availability of ants in the nests, Mongabay contributor Charles Mpaka reported in February 2025. “We realized that the fact that the chimpanzees in our study were going back to the same ant nests, even though these were almost never visible, was really important because it suggested that their repeated ant nest visits were not opportunistic, but rather that the chimpanzees relied on their memory to find the nests and revisit them over and over again,” said study co-author R. Adriana Hernandez-Aguilar. Remembering friends and family Another study found that chimpanzees also have rich, long social memories. In an experiment, zoo chimpanzees and bonobos were shown images of former group mates and of individuals who were strangers. The participating chimps and bonobos paid more attention to the known faces than…This article was originally published on Mongabay