Thanks. I've been letting them peek out and start. I did quarter of 1 side open the shells if they peeked a hole and later it didn't change or take a half off of a couple that looked "shrink wrapped" I guess.
It sound like from this comment you are opening the incubator during the hatch-----if so it might not effect your final hatch where you live, but if I opened during day 19,20,21 my hatch percentage goes WAAAAAAAAAAAY down, having all kinds of shrink wrapping, etc, etc. My Family knows---"You Better Not Open My Incubator during that time----there would be WAR". Good Luck