Howling is a vocal form of animal communication seen in most canines, particularly wolves, coyotes, foxes, and dogs, as well as cats and some species of monkeys.[1][2] Howls are lengthy sustained sounds, loud and audible over long distances, often with some variation in pitch over the length of the sound. Howling is generally used by animals that engage in this behavior to signal their positions to one another, to call the pack to assemble, or to note their territory.[3] The behavior is occasionally copied by humans, and has been noted to have varying degrees of significance in human culture.[4][5]