I have a couple of hens that have been broody off and on for months. They have been sitting for 4 weeks now. I got some day old chicks today to swap out for the golf balls (i.e. the "eggs" they have been sitting on). I have a separate area for the mamas & babies so the other hens will leave them alone. Do I need to wait until dark to swap the golf balls and chicks? Or can I do it before then? Thanks!