Vacman
Chirping
I have straw in my hoop house. So far, that's worked out well for me but you could also use wood chips to reduce the mud. Then put straw on top of that. The chickens will scratch and mix that stuff up so you might have to redo it from year to year. I plan to take the straw with the chicken droppings and use it as a base for my compost pile next spring.