Wild chimpanzees filmed using forest 'first aid' / Wild chimpanzees seen giving 'first aid' to each other with medicinal plants / Chimpanzees use leaves to wipe bums and clean up after sex, study finds / Chimpanzees use medicinal leaves to perform first aid, scientists discover / First evidence of mother-offspring attachment types in wild chimpanzees / Chimpanzees drum with regular rhythm when they beat on tree trunks, a form of ancient communication / Chimpanzee groups drum with distinct rhythms, research finds / The truth about chimpanzees and empathy - and what it tells us about human behaviour