Christmas came early for you, I guess! I wish I had "someones" like that in my life.
I really don't know if steel wool would work or not. I am sure hardware cloth would work, but we all know that hardware cloth is rather expensive.
Have you considered filling those areas with pallet wood? I would think it would take a mouse a very long time to chew threw 3 inches of pallet wood filler. And, if they did, you could just replace with more pallet wood. Probably buy you enough time to see if rodents are even going to be a problem for you.
I had a few mice move into my chicken coop this winter. Not a big deal for me because my feeder is suspended on a chain up off the floor. I don't think any mice can get to the feed. They might have to scrounge around on the floor looking for bits and pieces that might have fallen out of the feeder and that the chickens did not eat. I have one of those
tincat mouse traps that catches mice alive. If I had to trap mice in the coop, that is what I would use. No snapping traps around the chickens.
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