In my run I laid thin bricks along the whole perimeter of the run on the inside, and no one has dug under them because the bricks just fall into the hole if they try to so they give up very quickly.
I am an old user but I never actually introduced myself properly so here it goes!!
(1) Are you new to chickens / when did you first get chickens? - I got them 1 year ago, but I have had previous flocks
(2) How many chickens do you have right now? - I have 12 chickens currently
(3) What...
if it is a single stall horse barn i think its safe to get some more.... i have 12 big hens in a coop smaller than that and they are happy as can be with extra space even!
Hey Wisconsin Buddy! I'm here too! DEFINITELY insulate! My coop is, and it still can get chilly in there! We made our own plans so I don't have any recommendations on that, sorry. What breeds do you have? I have Barred Plymouth Rocks and Partridge Plymouth Rocks, and 2 bantams.. 12 total:)...