I want to hand raise some Mandarine ducks. I bought 7 eggs off EBAY and put them in an incubator. 2 of the 7 were alive and well at 27 days, but never hatched. I would like to try again. (I'm sure I did something wrong as it was my first try to incubate) I have a young Magpie duck hen and some young chicken hens. I"d like to have them sit the eggs for me next time. Mandarine eggs are pretty pricey. Just not sure how? Do I wait til they are already sitting and swap their eggs with the Mandarine??? Any advice would be greatly appreciated.