Adult brown bears defend themselves by using their paws, which are equipped with 4-inch-long, razor-sharp claws. Often they engage in threatening postures and vocalizations in an attempt to drive off perceived threats before engaging in physical conflicts. Unable to climb trees like black bears, mature brown bears usually stand their ground if they cannot flee a threat.

Adult brown bears have few natural predators. North American brown bears need only fear humans and larger bears, while those living in Asia must also cope with tigers. In contrast to the adults, young brown bear cubs are vulnerable to a range of predators, including wolves, coyotes and mountain lions, as well as other brown bears. Fortunately, young brown bears can climb trees to avoid danger. Mothers often send their cubs into the trees when they sense danger. When the danger has passed, the mother emits vocalizations that signal the cubs to return to the ground. The cubs stay with their mother for an extended period of time, learning how to hunt, forage for food and avoid danger. In some cases, this learning period may take up to four years to complete.

Brown bears also use their impressive claws to obtain food. Though they look large and clumsy, the claws are quite dexterous, and bears can use them to dig, pry open rotten logs and manipulate small objects.