I had a 50% hatch rate of which i am happy about. My humidity stayed good and so did temp but the last 3 got like superglued into their egg so i had to go in and get them. They had pipped and zipped but glued as they zipped what causes tht? On the remaining eggs i eggtopsied and the chicks fully developed but never externally pipped so what causes tht? Wanna try another hatch end of the month any advise or pointers to help make my next hatch any better would be apreciated. was a still air hatch .