A group of killer whales is called a pod. These pods consist of family members traced through the maternal line. Three different types of pods have been identified: resident pods, transient pods and offshore pods.
Resident pods are stable groups that live in one place. Transient pods move from place to place and feed on other marine mammals, such as whales and seals. Offshore pods travel along the coast and have the widest range. Killer whales have a system of underwater communication consisting of whistles and clicks, but members of a pod have their own unique collection of sounds.
Pods consist of between 2 and 15 individuals, but, sometimes, temporary pods of hundreds of individuals form, mainly for the purposes of mating, interacting with one another and catching prey when they appear in large concentrations.