I am hatching eggs in my kindergarten class. This is my third year and in the past I have had about a 60% hatch rate. The problem is I usually start my eggs on a Monday afternoon (late) because I dont want them hatching over the weekend when the kids are not here. My eggs usually arrive on a Friday and I keep my room cool over the weekend and this seems to work just fine. This time they arrived on a Thursday and I am worried about letting them sit an extra day. Is there anything I can do to help them sustain hatchability?