This behavior is an example of the instinct. Hibernation is one of the most popular facets of bear life. The start depends on meteorological factors, food availability and individual characteristics. In general, adult males remain active longer and leave the caves first, while pregnant bears are the first to enter and the last to leave, in the company of their offspring. Before hibernating, bears go through a period of hyperphagia and consume large amounts of high-calorie foods, increasing their fat layer for hibernation. Physiologically, the hibernation of the bears consists of a state of dormancy or winter lethargy that lowers their heart rate from 40-50 to about 10 beats per minute, the respiratory rate drops by half and the temperature is reduced by 4 or 5 degrees .
