Hubby made a sliding pop door for the coop - it slides up and down on the inside of the coop. There's a 1.5" lip on the outside of the coop the door slides down into/behind, but litter can get in the way so it doesn't go down the full distance. Can raccoons jimmy that up? I was thinking of covering the outside of the door with aluminum flashing - it worked great for the top of the nest box, they can't land or sit on it now, it's slanted and they can't get a grip. I'm thinking the same thing would apply with that door. It's just a piece of plywood, 10x13, so it isn't that heavy. Thoughts?