I have 10 baby chicks that hatched yesterday and during the night. I have two more that are pipped, one that died half-way zipped (???), and the remaining 5 eggs aren't even pipped at all. Today is day 23. Last time I candeled (day 12 maybe) everyone was alive and well. I'm wondering why they aren't pipping? Does this usually happen? Should I wait another day or make a small crack in the air cell? (hate for them to be rotten.....?)