Be careful to make sure there are no sharp wires to hurt their feet. Either bend the edges under or tape them up. As the chickens mature, you will need to provide them with a shelter that meets their basic needs. The ideal chicken coop will protect chickens from rain, wind, and temperature extremes. There should be perches adequately spaced and arranged so that the chickens can perch comfortably.
Chickens do better when they roost at night up off the ground.
And they're happier, also. It is the natural way for a bird to sleep. It helps prevent external parasites and keeps them from lying in their own droppings. You also don't want them to start sleeping in the nest boxes. Some kind of litter such as straw or wood shavings should be spread underneath the perches and needs to be changed when it becomes wet or soiled.