Sleeping. Most polar bears sleep for seven to eight hours at a stretch and they take naps, too. In that way, they're a lot like people.
On the ice in spring and summer, polar bears tend to sleep more during the day than at night, probably because seals are more active at night. But day and night hold little meaning in the Arctic where there are 24 hours of daylight in summer and 24 hours of darkness in winter.
Polar bears nap just about anywhere and any time, and especially after feeding on a seal. Napping helps bears conserve energy. A polar bear's entire existence centers on hunting and conserving energy.
Bedding. In winter, polar bears sleep in shallow pits they dig in the snow with their sides or backs to the wind.
Polar bears sleep right through blizzards in day beds dug in the lee of a ridge. The snow piles up on top of them and provides an insulating blanket. Sometimes they stay curled up under the snow for several days until the storm passes.
In summer, polar bears curl up on the tundra or on an ice patch, sometimes using a block of ice or an outstretched paw as a pillow. Landlocked bears dig sleeping pits in the sand or in gravel ridges along the shoreline.
In most of the Arctic, pregnant females dig maternity dens in snow banks in fall and give birth to cubs in early winter. Until March or April when they emerge from the den, mother and cubs spend much of their time sleeping.