Rat Catchers, Madamba, Mozambique

Some rat-catchers in Europe would raise rats instead catching them in order to get more money from the towns. This, and the practice rat-fights, could have led to rat-breeding and the adoption 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.