In reality,,, your hens will scratch in your run area,,,,,, not soo much inside coop. I recommend walkin coop 500%,,.
I also would not be overly concerned with the ground squirrels. Doubt, they are after eggs,,, and chicken feed,,, well if they are hungry,, that would serve most animals.
Feed your chickens inside run area,, and remove feed for the night and secure inside metal containers. You can also empty out the water containers for the night. This discourages night time wanderers from making a drink stop, knowing water is usually there. They still will find water, but not in your coop/run area.
I suggest you look into a perimeter HC apron buried shallow around coop.
If you do encounter severe digging ,, you can see the openings. Easy solution,, is to flood those chambers. Capture the escaping squirrels and relocate 3 miles away.
Caveman not in favor of killing anything.
