I have a buff orp hen that went broody. No fertile eggs available for her to sit on. I ordered a dozen of fertile eggs from Myer this morning. They will be here Sat. I have a cage that is in the coop that is 2x3x8 that I can make into a brooding cage but have no idea of what size to make the nest box for the hen, eggs and hatched out chicks. When I go to place the eggs and hen into the cage with the eggs in the new nest box will she just go in and sit? Should the new nest box need to be enclosed with an opening that the hen and chicks have access? I had no idea fertile eggs would be so cheap. 2.35 a dozen and includes free shipping. New to this so I have many questions. John