How do polar bears communicate with another polar bear?

Yes. Although it is extremely rare, polar bears may kill or eat smaller bears, or kill cubs from another bear.

Because They Live In Snowy Areas. Snowy Areas Such As Antartica And The Arctic Are Very Snowy Areas. Polar Bears Live In Arctic. So Don't Be Fooled When You Think That Polar Bears Eat Penguins....

The polar bear is called a polar bear because it is a bear, and lives in the area of North pole in the Arctic.

Only if it's a male bear that has happened upon some bear cubs yes. Otherwise, no, polar bears do not eat each other, they'd rather eat seals, whales and walruses than another bear.