It has tunnels that lead to other rooms. The polar bear uses their claws to dig the tunnels. It takes a long time to make it's home because it is so big. Polar bears are endangered for many reasons. One reason is because of water pollution.
Water pollution is when their food get polluted by oil spills and other kind of pollution.
Some of the animals that the polar bear eats live in the water pollution . And polar bears eat those animals and they die. Another reason is because of hunters. Hunters kill polar bears for their fur to make coats and rugs. It was fun to study about the polar bear.