Donkeys bray to communicate with other donkeys and their owners. A donkey's bray, also referred to as a hee-haw, is unique, and each donkey sounds slightly different.
Due to their distinctive and loud bray, donkeys are sometimes used as guards for livestock such as goats, sheep and calves. The guard donkey bonds with its stock and becomes aggressive if the herd is threatened. They remain alert while grazing and have a large visual range that assists with detecting predators. The donkey's bray is loud and startling to many predators and can chase them away before they do any damage. If the predator continues to advance, the donkey may charge, bite, kick or slash at it with its hooves.