I'm really new here and new to all this! I have 6 chicken eggs in an incubator, today is day 21. Two days ago I heard chirping from the incubator. I checked very quickly today, as there was no more chirping and no external pips and the air cells in all eggs are now pretty big (I think bigger than average), two chicks have definitely pipped internally. I don't know when however as I can't tell where the chirping was coming from two days ago and I don't know if I should be thinking of helping them with a safety hole or not...?!