I have them too and have accepted the fact that humans have been fighting mouse infestations for 1000's of years with no 100% solution. Simple fact is dryer sheets, peppermint oil, poison, closing up cracks, etc. may lessen their intrusions, but they will always find a way back in. If there was something that worked 100% of the time, that'd be THE method sold to us folks dealing with infestations. My "theory" is that mice know their place; they're a prey animal, not a predator. They are looking for food and shelter. They stay out of sight as best they can because they are a prey animal. They get comfortable with an environment; disrupt that with odd smells (peppermint oil or dryer sheets), they may look for a more comfortable place to hang. The nests I've found in the shop are loaded with bedding and reek of mouse pee; so they are repelled by the smell of dryer sheets but relish the smell of ammonia?
Below are some of my infestations in the shop. Worst one was in the insulated wall of the shop, buggers chewed through the 1/2" foam insulation panel, up the skirt board at the "outie" in the barn steel and into the wall. My shop is in a 40x56 barn that was later extended by 40' (40' x 96' now). The original was built without a mouse guard at the bottom of the steel, addition had it put in though it's little deterrent as the 40' x 40' addition has two 16' slider doors with 3" openings under (dirt floor). I ripped pressure treated 2 x 4's in half and screwed the 2 x 2's under the steel panels on the original barn which (I believe) has done a good job keeping them out of the finished walls.
I use TomCat poison in block form in the corners and under shelving. Again, my theory is that they stay in the shadows as they are prey and know it. I also have a few multi-mouse traps that don't need resetting. Those are stuck in behind racks and shelves, I usually catch a couple dozen through the winter, not too many in the summer.
Good luck! If you find a 100% solution, patent it and become a billionaire!
Bruce
A funny sound while running my drill press. Go figure, maybe ran up the table rack and somehow got into the top side?
Clausing lathe "sounded funny"; turns out the belt drive works well as a mouse shredder. I leave the under-headstock door open and have TomCat poison in the base under the motor.
Original barn where they chewed through the 1/2" foam sheathing under the barn steel and got into the wall.
Barn addition mouse gaurd
2x2's screwed to the skirt board butted up to the bottom of the steel panels on the original barn.
Multi-mouse trap, flip open the top and add seed. My record is 14 in the trap though it's an inauspicious record!