Orcas, also known as killer whales, have been observed creating seaweed tools in order to massage each other, a study suggests.
In a routine researchers are calling allokelping, orcas bite off a length of kelp, then position it between themselves and a partner before rolling the seaweed between their bodies. Scientists suggest this strengthens social bonds and promotes skin health.
The strange ritual was documented in drone footage of southern resident orcas from the inland waters of the US state of Washington, for a study led by the Centre for Whale Research (CWR) in collaboration with the University of Exeter.
