We also show no mercy. Mice have found refuge in our attic at some point, urinating in the same spots, and the ceilings got stained, of course. Initially we thought it was water damage, but alas, no. So we have traps in the crawl space, and in the attic. And squirrels are equally destructive. They like - among other things - to get under car hoods and chew on wires. Had my AC system wiring gnawed on, and after our February 10-day trip they snacked on another wire that made my car suddenly loose power.... about a mile from home, of course.