They have access to the ground but not during the day while im at work. When I get back home I move them into another run that is set up on the grass. In terms of being able to dig into the earth- can I just have a deep layer of pine shaving in the run that is set up on the patio? I noticed even now the chicks would dig through the pines in their brooder and almost like want to go underneath and use the pine shaving as a blanket.
Midday in the worst of the heat is when this is the most beneficial.
If you can alter your setup to make the extended run more secure when you're not home it would benefit them over the long term.