Chimpanzees use rhythmic drumming on trees to communicate over long distances, study finds.

Chimpanzees use rhythmic drumming on tree trunks as a form of long-distance communication, according to a study in Current Biology. Western chimps favor a steady beat, while eastern chimps vary their intervals. This ancient behavior may have evolved from the last common ancestor with humans around 6 million years ago and could provide insights into early human social communication.