Killer whales, also known as orcas, are large marine mammals that belong to the dolphin family. They are apex predators, meaning they are at the top of the food chain and have no natural predators. Orcas are highly intelligent and social animals, living in pods and communicating with each other through a variety of vocalizations. They are found in all oceans around the world and are known for their distinctive black and white markings. The term 'killer whales' is derived from their predatory behavior, as they hunt and feed on a variety of marine life.