Killer whales make seaweed 'tools' to scratch each other's backs | Daily Mail Online

Killer whales have been seen detaching lengths of seaweed and using them to massage each other - the first evidence of tool-making by marine mammals. Scientists spotted this behaviour in drone footage of 'southern resident' killer whales in the Salish Sea, in the inland waters of Washington, USA. Whales of all ages were seen doing this, possibly to strengthen social bonds and promote skin health. The study was led by the Center for Whale Research (CWR), in collaboration with the University of E