Killer whales have been caught on video breaking off pieces of seaweed to rub and groom each other, scientists announced Monday, in what they said is the first evidence of marine mammals making their own tools.
Humans are far from being the only member of the animal kingdom that has mastered using tools. Chimpanzees fashion sticks to fish for termites, crows create hooked twigs to catch grubs and elephants swat flies with branches.
