The polar bear is the largest living land carnivore in the world today, with adult males growing up to 2.6 meters in length. The most well known of all bears, the polar bear is immediately recognisable from the distinctive white colour of its thick fur. A polar bear is so well insulated that its body heat is virtually invisible to a heat sensor. The only unfurred parts of the body are the foot pads and the tip of its nose, which are black, revealing the dark colour of the skin underneath the pelt. The neck of the polar bear is longer than in other species of bears, and the elongated head has small ears. Polar bears have large strong limbs and huge forepaws which are used as paddles for swimming. The toes are not webbed, but are excellent for walking on snow as they bear non-retractable claws which dig into the snow like ice-picks. The soles of the feet also have small projections and indents which act like suction cups and help this bear to walk on ice without slipping. Females are about half the size of males.
Polar bears feed primarily on ringed seals. Bearded seals are taken less often than ringed seals, but are important prey items. Polar bears also eat harp seals and hooded seals, and they scavenge on carcasses of caribou, musk-oxen, whale, walrus (usually pups) and seal. They occasionally eat mammals such as Svalbard reindeer and lemmings, as well as birds, eggs, lichens, moss, berries, grass and kelp.