I was told that is due to the humidity being too high. I had one that was a few days from hatching and I touched it and it exploded. I was told it was because the chick had developed too much and had no room to move to get free.So I candled the eggs I put in on 7/11 and all look good..unfortunatley, some look way developed.. one even shows a developed chick., head, eyes, body shape, good size too.. some are dark areas taking up at least 3/4 of the shell. Is it possible the hen or the weather started these eggs befopre I did? When do I take them out and put them into lockdown? I do have another incubators with some ducks in it that are supposed to hatch in 3 days.....I thought this chicken hatching would be fun but its becoming a PITA....