Mice tend to follow walls so set traps so the trigger is in their path. Set numerous traps and set a trap no more than 10 feet apart where mice are active. Live traps for mice are also available. Be sure to release them far from any structure. Poisons are available.
Some baits cause death only after the baits are fed upon for several days.
Poisoning mice has some real disadvantages. Poisoned mice usually die in wall voids causing odor problems and insect activity. Sound and electrical devices show little evidence in driving established mice from buildings. Although mice are easily frightened by strange noises, they quickly become accustomed to repeated sounds. Ultrasonic sounds have very limited use in rodent control because they are directional and do not penetrate behind objects.