Polar bears are among the largest predators in the world. They range in color from pure white after a molt to a yellowish shade resulting from solar oxidation or staining by oil from seal blubber. Their skin, nose and lips are black in color. Polar bears’ long neck and narrow skull aid in streamlining the animal in water, and their large, flat and oar-like front feet make them strong swimmers. Their fur is thicker than any other bears’ even covering their feet, for warmth and traction on ice. Polar bears also have a thick layer of blubber which provides buoyancy and insulation.