Polar bears "still hunting" on the sea ice – waiting for an opportunity to grab an unsuspecting seal as it surfaces to breathe.
A hunt starts with a scent. Polar bears can smell seals up to 20 miles (30 km) away, often by the scent left on their breathing holes. The Arctic is home to millions of seals, which become prey when they surface in holes in the ice in order to breathe, or when they haul out on the ice to rest. In the fall, when the ice is softer, seals cut holes in the ice so that they can come up for air when they need to breath.
Polar bears find such breathing holes and wait, sometimes for several days, until a seal comes up for a breath. Polar bears hunt primarily at the interface between ice, water, and air; they only rarely catch seals on land or in open water.
The polar bear's most common hunting method is called still–hunting. When a polar bear spots a seal coming up for air, it gets down on all fours, delicately putting each paw on the ice to keep silent. The bear then makes a shallow dive through the hole to grab the seal with its claws. Those sharp, 2–inch claws grip the seal extremely well. Still, seals sometimes get away.
Polar bears have been known to get upset when they lose their prey, pounding the ice or throwing blocks of it in a sort of tantrum. When the hunt is successful, a bear will share a kill with others as long as they beg properly: keeping low, circling the kill and occasionally nudging the hunter with their noses.