Last fall/winter I was just slammed with mice in my shop. I put out traps and was getting 3-4 every day at the worst of it, but they were just replaced by 5-6 the next day! Over the spring and summer, I bought a bunch of these and made some bait stations from 2" PVC pipe. I put 1 in the gardens, 2 in the chicken area and 2 in the feed shack.
https://www.amazon.com/Ramik-Neogen-...%2C169&sr=8-32
Those worked absolutely awesome! I have not had a single mouse/rat in the shop yet this year and they are even staying out of the feed shack. (So I bought a case of them yesterday.)
I have to get some more PVC and make a couple more stations for inside the shop because I am sure the little bastards are just waiting for me to let down my guard. But I am a "true believer" in that stuff!