What works for mice dosen't seem to work for Red Squirrels. They ate the injector wires off my truck, $1500 and chewed holes in our shed and I tried about everything. If I plugged the holes they just chewed another. I finally lined almost the whole inside with metal screeening. Things are very hard to shot with a pellet gun, live in town so a shotgun is out. I caught one in a live trap after much effort. The only thing that seems to keep them away is "Critter Ridder" I get at Tractor Supply. Have to reply often and can't be used on painted surfaces but does do the job.