Although they are rarely heard and often considered silent animals, giraffes communicate with each other through infrasonic sounds and can also produce a variety of vocal noises ranging from snorts and grunts to hisses and flute-like sounds. Calves are summoned by their mothers through whistling sounds and the young giraffes respond by mewing or bleating. When courting females, male giraffes may produce a loud and harsh coughing noise.
Giraffes usually produce sounds to warn other giraffes of danger and their use of infrasound enables them to communicate long distances. Although they are usually found in groups, they develop few strong social bonds and the members of a group can change over the course of a few hours. Up to 32 giraffes can make up a group, with the more stable groups being those made up of mothers and calves. The social cohesion of a stable group is helped by the bonding between calves. As the males grow older, they become more solitary and may wander far from the areas they normally frequent. Giraffes possess a home range, but are not territorial.
Mother giraffes with their calves may gather in nursery herds known as calving pools. Adult males display little involvement in raising calves, but mother giraffes will defend their calves by standing over them and kicking at an approaching predator. The bond between a calf and its mother can last as long as until the mother's next calving.