The brown bear weighs between 100 and 635 kg. It lives in Russia, northern Europe and North America and is the largest meat-eating animal living on land. Most bears eat a wide variety of food, both meat and fish, but 90% of their diet comes from plants. In the winter, their fur is long and thick. In the summer, their fur is short and thin. In the summer and in the autumn, they eat a lot of food. They build up a layer of fat so that they can survive during the winter months. In winter, they sleep a lot, usually in a safe dark place such as a small cave in a hill or mountain, or under a tree. Brown bears are beginning to move into towns and cities to look for food.