Sorry I know this information has been covered on here before, but I cant find it. I have a golden phoenix hen who has made a nest and has been laying eggs in our shop. She has 6 eggs in there now. I don't know how many she will lay before she starts sitting. I also have a few duck eggs that were laid by our pond, although I'm not sure which girl laid them. We have several different breeds. I was thinking about slipping the duck eggs into the chicken nest, but I didn't know when to do it. Do I put them in now or wait until she starts sitting on the nest? I have read that chickens are 21 days and ducks are 28 days, but that sometimes the chicken will stay on the eggs until they hatch because they feel the eggs are good? Does that sound right? Or will she have her chicks then abandon the other eggs? Sorry for the questions, just didn't want to screw up. Thank you.