I'm converting a pre-existing building on my property into a new coop and run. The building has a rock floor (those sort of medium size grey rocks). Should I shovel those out and either leave the dirt (actually, I'm not sure what's beneath the rocks- they're pretty deep) or replace with new bedding or put new bedding on top of the rocks? I am content to leave the rocks if they will be ok flooring- I'm thinking I can hose them off when cleaning time comes around? This is my first time building a coop! Any input is greatly appreciated. Thanks in advance!