🦦 Sea Otters Have Favorite Rocks — and They Carry Them Everywhere
Sea otters, the smallest marine mammals, hide a fascinating secret beneath their furry forearms: built-in skin pockets. These natural pouches aren’t just for snacks—they serve as tool belts for one of the otters’ most prized possessions: a favorite rock.
Researchers have found that many otters select a particular stone, which they use as a hammer or anvil to crack open hard-shelled prey like clams, mussels, and sea urchins. What’s even more astonishing is their loyalty—some otters carry the same rock for months, even years.
This behavior highlights their impressive intelligence and tool-using abilities, skills rarely seen outside primates. For female otters, these tools are especially crucial. Smaller and with weaker bites than males, females rely on rocks to access calorie-rich prey, fueling the high energy demands of raising pups. Young otters learn by watching their mothers, ensuring this knowledge passes down through generations.
Beyond survival, otters’ shell-cracking habits have an ecological ripple effect. By controlling sea urchin populations, they help protect kelp forests—vital underwater ecosystems that shelter marine life and capture carbon. In short, every rock an otter carries is also a key to healthier oceans.
đź“– Source: Mihai Andrei (2025, February 20). Sea otters have a favorite rock that they keep in a fur pocket under their arms. They have a clever reason for it. ZME Science.
