It is the smallest species of marine mammals, belonging to the Weasel family, mainly distributed along the North Pacific coast. Known for its social behavior, ability to use tools, and adaptability to the environment. Their body shape is relatively short, streamlined, and covered with dense two layers of fur. The outer layer is long and rough needle hair, and the inner layer is short and soft bottom hair, which allows them to maintain body temperature in cold water. It is a carnivorous animal that mainly feeds on sea urchins, shellfish, and other marine organisms. The unique behavior of using stones as tools to break open hard shells is quite rare in the animal kingdom. It is a unique and precious marine organism.