@Lacrystol I have a question that maybe you can answer. I have 8 duck eggs mom is sitting on them. The air cells dipped about three days ago. I can see shadowing in the air cell on two since almost two days ago. They are moving around still. I think they rested for a while earlier, but checked tonight and they are moving, but not as strongly on two. I can't hear anything. Yesterday I saw the one poking toward the air cell alot, without any progress. How long should it take them from the internal to external pip? Also will there be peeping once they break through the air cell? All but one egg has hairline cracking. Not sure if it's from them or mom. I was just worried they may be stuck. Also I don't know exact date of when she started sitting.