Hey, my chicks are about 5-7 days old. When should I introduce grit into their cage. I was told just to sprinkle it around their box, they will know what to do with it. Is that true? I also bought a cage/coop that will last them 6 months. The roost is a round stick about 1 inch in diameter. They are out growing their little brooding box could I move them to that?