Cubs nurse in the den. After about six weeks, their eyes open. In about two more weeks, they walk. They leave the den when three months old, are weaned by seven months, and by fall usually weigh 60-100 pounds. Bears traveling in groups in autumn are usually females and their cubs.
Cubs are playful, romping in water and wrestling with their littermates.
The female protects them, sending them up trees if danger threatens. Males occasionally kill and eat cubs. In most cases, cubs den with their mothers for their first winter. The family group disbands the following summer, when the female again is ready to breed. A female generally raises only one litter every two years.