Females start to mate in their third year producing only one cub. Sows then usually mate every other year producing two cubs. The mother bear often lies on her back or side to feed her cubs but sometimes sits on her haunches and holds her cubs on her lap much like a human mother. The cubs stay with their mother through a second summer. They are very playful and investigate everything.
Male bears take five or six years to mature.
Other than man, black bears have few enemies. Wolves may attack young bears or a pack may attack females. Grizzly bears may also attack brown bears. This seldom happens. More brown bears die from accidents and disease than from natural enemies.