Females do most of the caring of the young, while males play no role. A female often has an older offspring with her to help socialise the infant. Infant orangutans completely depend on their mothers for the first two years of their lives. The mother will carry the infant while travelling, and feed it and sleep with it in the same night nest. For the first four months, the infant is carried on its belly and almost never without physical contact. In the following months, the time an infant spends with its mother decreases. When an orangutan reaches the age of one-and-a-half years, its climbing skills improve and it will travel through the canopy holding hands with other orangutans, a behaviour known as "buddy travel". After two years of age, juvenile orangutans will begin to move away from their mothers temporarily. They reach adolescence at six or seven years of age and will socialise with their peers while still having contact with their mothers. Females may nurse their offspring for up to eight years. Typically, orangutans live over 30 years both in the wild and in captivity.