A working cat, also known as a mouser, is type of domestic cat that "works" for its keep by hunting vermin, such as rodents. They are commonly employed where pest control is needed, such as barns, farms, factories, warehouses, stores, churchyards, and private property.[1] Types of working cats include the bodega cat, farm cat, ship's cat, and library cat. A benefit of using a working cat is that they alleviate the need for harmful pesticides.[2] Working cats are often placed in their environment as a part of a working cats program.
The resident cat at the British Prime Minister's home at 10 Downing Street has been given the title Chief Mouser to the Cabinet Office.[3]