Deep as in 3 or 4 inches, not more. It could work and you won't know unless you try. They will love scratching through it, far more than sand. As for the floor door, seal that up and make a pop hole in the side into your, ahem, extended run!
Dogs can be taken for walks. Chickens only have the space you give them.
Incubator, now that's dangerous talk!!
Dogs can be taken for walks. Chickens only have the space you give them.
Incubator, now that's dangerous talk!!
