Firefly, you need to keep them from coming in so seal off any holes you see, even very small and never leave doors open. We used to get them from the garage when I would prop the door open to bring in groceries. They are sneaky and not afraid to run by you.
Also make sure all kitchen cabinets are fully sealed so if you do get mice its less mess to clean up. I bought a can of foamo and sealed up all the openings between the kickboards and the bottom of the cabinets.