Researchers have captured the spread of a new type of tool use in a wild population of chimps.
They say this is the first clear evidence of wild chimpanzees developing a new culture.
As the team filmed the animals at a field station in Uganda, they noticed that some of them started to make a new type of leaf sponge – something the animals use to drink.
This new behaviour soon spread throughout the group.
The findings are published in the journal Plos Biology.