Most monkeys are arboreal creatures that inhabit tropical or subtropical areas. Unlike apes, they do not typically swing through the trees with their arms, but instead run swiftly along the branches. The vast majority of the mammals are most active during the daytime and have no permanent shelter, choosing instead to travel on a continual basis in search of food. Social animals, monkeys usually carry out this process in sizable groups that may contain as many as several hundred individuals. Breeding may take place anytime amongst many species, but some seem to adhere to a seasonal cycle. Females usually bear only one infant at a time and are heavily involved in caring for the young, often for an extensive amount of time. Some male monkeys also actively take part in child rearing.