Any experiences with electronic mouse repellers? There's some snake oil around (e.g. the "electromagnetic" repeller that "penetrates walls, ceilings, and floors") but do the ultrasonic ones actually work?
The problem exists only in our kitchen and laundry room, which would be very difficult to seal. SWMBO uses 'bait' with some success but it needs constant attention and seems unfriendly. One repeller in each place would be better, if they worked.