Sea pigs (formally known as "Scotoplanes") are found in every ocean in the world. In some areas, they represent more than 95% of the total weight of animals found on the deep-sea floor. Their home is in the coldest and deepest parts of the ocean, so they are seldom seen by divers. They are a type of sea cucumber which is part of the group of marine animals known as echinoderms (this group includes sea urchins and starfish).
Sea pigs often congregate in groups of many hundreds of individuals, drawn to one area by a large feast (e.g. a dead whale carcass). While feasting, they can frequently be observed to be facing the same direction (usually into the prevailing current).