Here's why:
* Hunting: Polar bears are apex predators that rely on seals for food. They hunt by waiting near breathing holes in the ice or by ambushing seals on land.
* Travel: Sea ice provides a platform for polar bears to travel long distances, searching for food and mates.
* Denning: While they do den on land during the winter, they spend the majority of their time on sea ice.
So, while polar bears do visit land, they are primarily marine mammals and are much more at home on the ice.