I have a Orpington hen that was sitting on six eggs and she sat on the eggs all day only getting off for 10 to 15 min. Well after 28 days not one egg hatched so I waited till 31 day. But still not one egg hatched so I opened one egg and it was rotten.It turned out all the eggs where rotten. so I gave her 3 more eggs and they went rotten too. I have a roster with her all day. she has a nice nesting box, and nice straw but I don't know why her eggs aren't hatching. My roster is like five or four years old though, could it be that my roster may be infertile.