Monkeys That Use Rocks to Smash Nuts - Dorothy Fragaszy

Large animal predators have to work hard for their food. Lions take great risk to chase down zebras and wildebeest. Polar bears wait very patiently by holes in the Arctic ice until a seal shows up. But just because they aren't eating other animals, capuchin monkeys work for their food as well. National Geographic explorer Dorothy Fragaszy studies the primates in Brazil's Piaui state and says that the monkeys find rocks that weigh half as much as they do to smash open their nuts.