I have four eggs due to hatch this coming Saturday. I am on day 19 and have heard that on this day they should break through the air sack at some point. Wondering how soon after the breaking of the egg sack you can hear the chicks peeping or chirping inside the egg. Also is the ability to make peeping sounds a sign that they have broken the air sack? The eggs make small movements from time to time, is that the chicks getting into position or would it be them trying to break the air sack, or both? Thank you for any info!