Ok ive been incubatong some eggs and they arent hatching on due date. So i waited a week and opened them yhe chicks were alive but not ready. Idk why. The yolk sack eas still there. Ive check humdity and looks great nut i did notice my still air Styrofoam incubator wasnt hold temp a night. Cant figurr that out either i need help i've already lost 4 dozen dang good eggs.