A rat-catcher is person who practices rat-catching, the occupation of catching rats as a form of pest control. In developed countries the role may be merged with, or the title inflated to, pest control operative or pest technician. Keeping the rat population under control was practiced in Europe to prevent the spread of diseases to man, most notoriously the Black Plague, and to prevent damage to food supplies. A famous rat-catcher from Victorian England was Jack Black, who is known through Henry Mayhew's interview for London Labour and the London Poor.