While sharks are deadly marine predators, they also seem to attract fish looking for a'spa day' by rubbing against their rough skin. Drone footage recorded by marine biologists at the University of Miami captured frequent incidents of the surprising ritual. Researchers pored over underwater video, photos, drone footage, and even witness reports to find 47 different instances of fish rubbing up against a shark's body at more than a dozen locations around the world. The length of these regimens varied from eight seconds to more than five minutes, and included dozens of incidents of leerfish, also known as garrick, rubbing up against a great white shark, the ultimate oceanic apex predator, in Plettenberg Bay, South Africa. The number of fish chafing against a particular shark varied, too, from one lone swimmer to over 100 at once.