A pointless fashion trend or something else? Chimpanzees wear blades of grass in their ears and rears

A team of researchers from Utrecht University, Durham University, and other institutions have observed something remarkable at a chimpanzee sanctuary in Zambia. Several chimpanzees from one particular group were seen dangling blades of grass from their ear holes or their behinds, for no apparent reason. The behavior was not seen in other chimpanzee groups at the same sanctuary, despite similar living conditions.