Chimpanzees are copycats but sometimes it is more than copying, it becomes new traditions particular to only one specific group of these primates, according to a paper in Animal Cognition.
Edwin van Leeuwen of the Max Planck Institute for Psycholinguistics in The Netherlands
noticed how a female chimp named Julie repeatedly put a stiff, strawlike blade of grass for no apparent reason in one or both of her ears. She left it there even when she was grooming, playing or resting in Zambia's Chimfunshi Wildlife Orphanage Trust sanctuary. On subsequent visits, van Leeuwen saw that other chimpanzees in her group had started to do the same.