Body language
Bulls mark the boundaries of their territories with heaps of dung, secretions from their scent glands, and certain behaviors. Body language used by a territorial male includes standing with an erect posture, profuse ground pawing, and horning, frequent defecation, rolling and bellowing, and the sound "ga-noo" being produced. When competing over territory, males grunt loudly, paw the ground, make thrusting motion with their horns, and perform other displays of aggression.