We have 7 hens, 7 wks old. Their "yard" is 15'x14' the top is covered with fencing as well for protection. Their area is a combo of dirt and grass in a raised area that's about 8'x4'. We thinking about putting hay down in the lower area. It USED to be mostly grass, but they are having a wonderful time digging in the dirt. IS SPREADING HAY ON THE GROUND IN THE DIRT AREA A GOOD IDEA???