Extremely agile for their size, bears sometimes stand erect on their hind feet to see and smell better. Top speed is 30 miles per hour over a short distance. Black bears climb easily and swim well. Black bears have an acute sense of smell, but their vision is poor. Hearing is not believed to be acute.
Sows communicate to their cubs with low grunts, huffs and mumbles.
Bears are mainly nocturnal, but they sometimes feed and travel by day. Alert and wary, they tend to avoid open areas. Individuals are solitary. While most bears will run from a human, a female with cubs should be respected and on rare occasions might actually attack if she feels her young are in danger. Bears find food mainly by scent.