We've been using these traps for a few weeks now to deal with the critters in the shop & feed shed (same building.) This just might be the nicest little mouse trap ever made. There's a wee trap door in the back that holds about 4 servings of peanut butter. It fits into tight spaces, is incapable of smashing your fingers, doesn't need re-baiting every day, and the dogs can't get at the dead mouse. The dead mouse shakes out pretty easily or you can throw the whole thing away if seeing flat rodents give you the willies.