Mice in a cold room, pickup the Victor wooden snap traps preferably with the yellow plastic paddle, with the little hook to fasten your bait, mice are always looking for nesting material, and food, so take a piece of small cotton ball, and dab a very small amount of peanut butter on the cottonball, then hook the cottonball with peanut to the hook on the mouse trap, that way he or she has to work to get the bait, also mice can get through the opening the diameter of a pencil, so if you can see lite through it ie a door, mice can get through it, check all the lines coming into the house ie cable, gas, hydro etc, and make sure the caulking is still in place, mice are great climbers so dont be afraid to look up, etc where your hydro meter and line go through the soffit etc giving them access to your attick, any other questions pm me, and I will try to help you further as ive been an exterminator for 30 years