Long-tail macaques can be found frolicking in the seas of southern Thailand. It’s a wonderful place to play, socialize, and keep cool. It’s also the perfect place to enjoy a seafood banquet. These macaques are waiting for low tide conditions when they can find shellfish to crack open and eat. And they use rocks as their shell-cracking tools, as seen in this Wild Thailand clip from BBC Earth. From New Scientist:

They target the largest rock oysters, bludgeoning them with stone hammers, and pry open the meatiest snail and crab shells with the flattened edges of their tools.

These macaques are one of three primates that use stone tools, alongside chimpanzees in Africa and bearded capuchins in South America. “Stone tools open up an opportunity for foods they otherwise wouldn’t even be able to harvest,” says Lydia Luncz at the University of Oxford.

Next: Watch more monkeys and learn more about chimpanzee tool-use with Jane Goodall. Plus: Spend a Day With the World’s Only Grass-Eating Monkeys.

See more videos about...