I have two Marans hens that I want to get some chickies out of but their eggs will not develop. I have tried for the last few months with about 40 eggs and no devleopment of any egg. I know the rooster is doing his job, as I have 3 buff orps in the pen as well and getting 100% hatches. And obviously the incubator is doing its job. I have cracked open the eggs and they look to have the "bullseye." One hen has been laying since October the other since Feb. What is going on with these girls and their eggs!