Wolves are legendary because of their spine-tingling howl, which they use to communicate. A lone wolf howls to attract the attention of his pack, while communal howls may send territorial messages from one pack to another. Some howls are confrontational. Much like barking domestic dogs, wolves may simply begin howling because a nearby wolf has already begun.
Wolves are the largest members of the dog family. Adaptable gray wolves are by far the most common and were once found all over the Northern Hemisphere. But wolves and humans have a long adversarial history. Though they almost never attack humans, wolves are considered one of the animal world's most fearsome natural villains. They do attack domestic animals, and countless wolves have been shot, trapped, and poisoned because of this tendency.
In the lower 48 states, gray wolves were hunted to near extinction, though some populations survived and others have since been reintroduced. Few gray wolves survive in Europe, though many live in Alaska, Canada, and Asia.