The sperm whale is the world's largest toothed predator, and they consume as many fish and squid as the entire global fishing industry. However, we have not, until recently, understood how such large predators find their food in the deep ocean. By putting a data logger on the tip of the nose of a sperm whale, researchers from Aarhus University have gained the first insight into the world of the prey a sperm whale is seeking out, and they can show that sperm whales hunt with the help of a long-distance sonar.