Free: Contests & Raffles.
I would politely tell them that coyotes ate the local cats that were keeping the mice in check. I would then point out that you exterminated those coyotes, so it is safe for them to get another cat or two to work the mouse population. They can even go to no kill shelters and specifically request "barn cats" that people have brought in that are exceedingly good killers but not so good with people. Give them a place in the barn or garage with a blanket and some cat food, and they will stick around long enough to find mice and rats. Then I would just say, "Oh, by the way, you're welcome," and walk away.Chris