There are many unanswered questions as to how sharks and other animals know when and in what direction to migrate. Researchers have proven that migratory animals such as birds or caribou use a wide variety of senses to navigate from one point to another. The most obvious are physical and visual cues, such as following river beds, coastlines or mountain ranges from the ground or the air. Birds, some fish, and turtles also navigate by following the sun, by light waves reflecting off water, by responding to the earth's magnetic fields and even by the stars at night.
Sharks navigate mainly by electro-reception and a sensitivity to pressure and water temperature.
One part of this system, the ampullae of Lorenzini , consists of jelly filled pores with external openings large enough to be seen by the naked eye. The shark's lateral line system helps it to have a sensitivity to pressure. It also helps sharks to orient themselves for direction and migration purposes. Together, the bio-electrical and lateral line sensors allow the shark to navigate, silent and unseen, beneath the surface of the ocean. In addition to aiding the shark in navigation, the ampullae of Lorenzini and the lateral line system are particularly important in helping a shark detect the presence of prey.