Yea, mice are sneaky. Our early warning system is our male dachshund. His nose is amazing. We have not had mice in the house, or if we did, he disposed of them for us. We have a storage building in the back yard, on concrete blocks to level the building on the slight slope. That is a prime critter hide out. When Reuben is circling the building, and won't come inside, I know it is time to set the traps. I have a old jar of peanut butter, and the trusty spring traps. Cram the peanut butter down into the trigger, and it works 95% of the time. Don't buy the super cheap knock off brands, get the Victor brand.
His favorite treat. He got a baby bunny earlier this spring that made a run from under the storage building. I did not photograph it, as it was kinda sad, and very very dead.