Polar bears are mostly solitary animals and are active at all times of year, always on the look-out for a meal. They are extremely strong and active and cover the ground quickly with long strides of their bowed legs. The soles of their feet are covered with hair to help them get a grip on slippery ground. Polar bears are also good swimmers using their front legs to propel them, their hind feet trailing behind. Keeping their eyes open and their nostrils closed, they dive beneath the surface and can stay under for up to two minutes at a time.
Winter
Some bears spend both summer and winter along the lower edge of the pack ice, sometimes migrating from north to south as this edge shifts. Others move onto the land in the summer and spread out across the ice as it forms along the coast and between the islands during the winter.
Any polar bear may make a winter den for temporary shelter during severe weather. Pregnant females can stay in their dens for up to three months to give birth to their young. They don't eat during this time, but live off their fat reserves. Males and non-pregnant females remain active all year.