Hey, I have rhode island red chickens about 6wks old. I set up the dog run by covering it w/ poultry wire and 2 boards over one end. They sleep in a Med. size dog carrrier cover w/ a clear plastic tote. I do not know what is the best floor litter to use since the run is sitting on a concrete slab. I put a pile of pine shavings in one spot and some play sand in another spot. Both r still fairly wet as it has rained here almost everyday this week. What is the bedt option to cover the bottom with? This will be used temporarily until I can find a more rural residence.