They have an incredible sense of smell, and they seem to trust their nose more than any other sense. Hearing and sight are also important, but to a lesser degree. A bear's hearing is probably better than ours, but not as keen as dogs. Their sight is probably comparable to that of a human. Where both species occur in the same area, black bears tend to favor forested habitats while brown bears favor more open areas.
Bears are opportunists, relying on their intelligence and their senses to find food.
They use differing habitats throughout the year, depending on the availability of food and other necessities of life. The amount of area a bear covers in a given year is partially dependent on how far it has to go to satisfy these basic needs. In some areas, individuals bears may have a home range of less than a square mile. In other areas, home range can encompass hundreds of square miles. Males usually range over larger areas than do females.