Researchers have used camera traps to film chimpanzees in the Ivory Coast making unique tools.

The footage revealed that the clever primates habitually make special water-dipping sticks - chewing the end of the stick to turn it into a soft, water-absorbing brush.

Primate researchers examined the "dipping sticks" and concluded they were made specifically for drinking.

The findings are reported in the American Journal of Primatology.

Footage courtesy of Juan Lapuente, Comoe Chimpanzee Conservation Project