I have a clutch of duck eggs getting ready to hatch beneath a broody hen. Two of the eggs externally pipped 24 hours ago but have not made much progress. Their bills are sticking out now and the membrane is a yellowish brown color. Do I need to assist? It was extremely dry weather the day they started to pip and I am afraid the membrane may now be too dry and hard for them to get through... And if I do need to assist, what in the world do I do?