Female and young male Asian elephants live in cohesive herds of related adults and their offspring. The matriarch, usually the oldest and largest female, sets the pace of the group's activities. Herds often join with others to form large groups called clans. Males leave herds at puberty, around their 13th year, and travel alone or in bachelor groups. Elephants wander widely in search of food. Movements vary widely depending upon food availability. Asian elephants communicate via rumbles, growls, bellows, and moans. Some of these varied, low-frequency sounds may travel a mile or more.