Bear Facts Did you know? -Bears have a excellent sense of smell and are very skilled runners, climbers, and swimmers. -Bears use caves and burrows as their dens; most species of bear occupy these dens during the winter for a long period of time for hibernation. -Some bears can hibernate for up to 100 days. -Some Polar bears have been known to reach over 2000 pounds. -The smallest bears are the sun bears of Asia weighing around the weight of a 15 year old human 99-150 lbs -The Brown Bear has been known to reach speeds in excess of 25 mph. -Bears’ non-retractable claws are used for digging, climbing, tearing, and catching prey. -Bears’ excellent sense of smell is better than that of dogs, or possibly any other land mammal.