When a pack of wolves sense something wrong with a bull, they leave the healthier ones behind to chase it instead. Subscribe to BBC Earth for more amazing animal videos - http://bit.ly/BBCEarthSub Watch more videos from BBC Earth: Planet Earth http://bit.ly/PlanetEarthPlaylist Blue Planet http://bit.ly/BluePlanetPlaylist Planet Earth II http://bit.ly/PlanetEarthIIPlaylist Planet Dinosaur http://bit.ly/PlanetDinoPlaylist Check out the other two channels in our BBC Earth network: BBC Earth Unplugged: http://bit.ly/BBCEarthUnplugged BBC Earth Lab: http://bit.ly/BBCEarthLabYouTubeChannel Natural World: A Wolf Called Storm Welcome to BBC EARTH! The world is an amazing place full of stories, beauty and natural wonder. Here you'll find 50 years worth of astounding, entertaining, thought-provoking and educational natural history content. Dramatic, rare, and exclusive, nature doesn't get more exciting than this. This is a commercial channel from BBC Studios. Service & Feedback https://www.bbcstudios.com/contact/contact-us/