A rat-catcher is a person who practices rat-catching as a professional form of pest control.
Keeping the rat population under control was practiced in Europe to prevent the spread of diseases, most notoriously the Black Death, and to prevent damage to food supplies.
In modern developed countries, such a professional is otherwise known as a pest control operative or pest exterminator.
Anecdotal reports suggest that some rat-catchers in Europe would raise rats instead of catching them in order to increase their eventual payment from the town or city they were employed by. This, and the practice of rat-fights, could have led to rat-breeding and the adoption of the rat as a pet—the fancy rat.
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.
Rat-catchers may attempt to capture rats themselves, or release "ratters", animals trained or naturally skilled at catching them. They may also set a rat trap or other traps.
Modern methods of rat control include traps, poisoned bait, introducing predators, reducing litter and clearing of current or potential nest sites.
A "ratter" usually refers to a dog used for catching or killing rats. This includes specially-bred terriers for vermin-hunting, which may be known as rat terriers, although the latter may refer to a breed that was historically developed in rat-baiting.
Rats are rarely seen in the open, preferring to hide in holes, haystacks and dark locations. A rat-catcher's risk of being bitten is high, as is the risk of acquiring a disease from a rat bite.