Sometime in December or January, two babies called cubs are born. The cubs are small. They would easily fit in a child's hand. The cubs are born blind, deaf and have only a tiny amount of fur. For the next three months, they will stay inside the den with their mother. She will keep them warm and her rich milk will keep them well fed. In three months, they will grow to the size of a human baby and will have a bright white coat of fur, just like their mother's.

In March and April as the days lengthen with the arrival of spring, the mother and her cubs leave the den. Together, they will explore their new world but will stay close to their mother's side. If frightened by other animals, especially other polar bears, they will climb on their mother's back for protection.

Polar bear cubs remain with their mother for two to three years. She will use this time to teach them how to hunt and how to avoid danger. Raising two hungry and playful cubs isn't easy, but a polar bear mother is very patient. She knows the wrestling and play battles are good for learning hunting skills.

At three years old, the cubs leave their mother and must use the skills she has taught them to survive. Next winter, she may have two more cubs to care for.