I'm new to this forum and new to chickens but not coons. The place we just bought had a nice coop and run built on it and I couldn't figure out why they just gave up on it. The niebors informed me they had a coon problem and that was the reason. I suspected that because there was an attached building to the coop full of coon poo. They had put concrete floors in the coop, cement around the bottom edge of the run and built nice strong doors and frames on everything. It all looked great. Yesterday I decided to clean the coop and inspect everything. Yep I found the access the little critter was using. Up in the corner between wall and ceiling was a small opening about 3 inches by 3 inches. Now I've read some of the post on here about coons and building things so they can't get in but I haven't seen anything on explainging what that means. You would be amazed at how big a coon can fit through a 3x3 opening. Just think of it as this if he can get his flat little head in it the rest will fit. I wouldn't have believed it but I once had to remove a coon from a commercial dryer that had made a home in the top of it. There wasn't a opening as big as the one in the coop and that little guy was living it up in there. I've also noticed claw marks and bite marks on the bottom of the run door from before. If I see fresh marks on the door then I'm going to set up a remote camera to see what it is. The other thing I did was remove 13 feral cats from the place.