We’ve bred smarter mice. Every year or two we have mouse problems but diligent live-trapping and releasing for a week or so has kept them under control. (I don’t doubt that mice remained in our walls/ basement, but if they’re not invading our living space I don’t have much of a problem with that.) This time our old traps were entirely ineffective- they were tripped, often with the bait stolen, but detained no mice. We bought another kind and caught a few. The captive mice often destroyed the more complicated mechanism of these traps, but we could live with that. Alas, we’re now encountering the same problem of the mice escaping after tripping the trap. We may be seeing evolution in action here- we took out the really dumb mice in past years and have already removed the dumbest offspring of those left.