Wolves form close social groups and are important predators in the areas they inhabit. After years of being driven out, the unearthly wild wolf howl is returning to its original North American range through re-introduction of captive bred wolves.  Before wolves head out to hunt, the pack often gathers together for a howling session. This haunting sound can be heard for miles, and on a dark chilly night, the mournful howls can sound pretty chilling, like this wolf howl ringtone.