I had 13 chicks hatch at days 22 and 23 of incubation. At the end of day 23, when the remaining 5 eggs hadn't even pipped, my husband and I opened them up to see what was going on, and all 5 chicks were fully developed but dead. Anyone have any idea why this happened? It was absolutly heartbreaking. Also, one of the chicks had zipped it's shell all the way around and then died.