By Larry, a four year old tabby cat.
Huzzah! Long overdue, I think. Hope he does a great job. Of course Wiki has an article on his time-honored post: Chief Mouser to the Cabinet Office - Wikipedia
Wouldn’t a dog be better able to handle a rat than a cat would? Cats are good at catching mice (and roaches and crickets).
Nice that they’re getting an animal and not just putting poison everywhere.