So I have two 12x12x12 nesting boxes for my three hens and I am not sure just how much hay to put in. The rest of the coop has rice hulls in it so I put a thin layer of that down and just kind of tossed a little hay on top and made it "nest shaped". Is there some kind of formula for how much material should go in? Also they are 23 weeks old and NO EGGS YET! I am not a patient man sometimes.