Gundawg
Chirping
I'm sure you will get various answers Mike. I put my internal nest boxes up at 18" off the floor so the space under them is usable by the chickens. You want them LOWER than the roosts. Chickens like to roost as far up as they can get and if that is the nest boxes, that is where they will sleep. Not what you want unless you like cleaning poop out of the nest boxes every morning.
On the floor, I'm not sure. If you rake around the chips every morning they pretty well mix with the poop, but that is the kiln dried pine shavings I get in compressed bales. Not sure how "raw" chips would work by comparison. Your "poop issues" will depend on how many chickens you have and if they can get out of the coop early in the morning.
It is possible the rough cut lumber will take on an ammonia smell over time if untreated (and don't ask me what to treat it with because I don't know)![]()
I have rubber horse mats (because they were in the barn stall when we bought the place) over hardware cloth on a dirt floor.
I had not thought of using horse stall mats and the great thing is I have 2 - 4x8 mats left here by the previous owners, that is a great idea I will need one or two more.
I had not thought about the chickens walking under the nest boxes I am glad I asked.
Mike