While filming orcas, Steve Backshall witnessed them hunting and killing prey, but not for food. He explains why they do this and how he’s processed this disturbing behaviour.
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 entertaining and thought-provoking natural history content. Dramatic, rare, and exclusive, nature doesn't get more exciting than this.