I have some ducks that are trying to hatch. So far it has been over 24 hours and both have a hole in their egg about one inch in diameter. It appears they are starting to dry out. Looks like the humidity is about 65-%-70%. I don't want them to dry out too much and not be able to hatch. Should I add more water, a spong, mist? Advice? The ducklings and I thank you!