The socializing males spend a lot of time "mutual grooming" - they use their teeth to `scratch' each other on parts of the body, such as the withers and back, which are difficult for a horse to reach himself. Mutual grooming is also important in establishing and maintaining social bonds between individuals. Although such grooming most often involves two individuals, in busy gatherings sometimes two or three horses are all trying to groom or initiate grooming with the same individual.