On World Wildlife Day, we"re in the ice-cold waters around the Norwegian island of Spildra with a pod of orcas, also known as killer whales. These apex predators are at the top of the food chain with a diet that includes a smorgasbord of sea creatures including fish, penguins, and even sharks and whales. They hunt in pods, family groups of up to 40 individuals that work together using special hunting techniques sometimes likened to packs of wolves. Despite their scary name, they almost never attack humans and there are no documented cases of wild orcas killing anyone. The name "killer whale" is thought to come from Spanish sailors who saw groups of them hunting big whales. Orcas are also the largest member of the oceanic dolphin family, Delphinidae.