I'm on day 20 and I'm getting to the point where I'm a nervous wreck. I'm getting a lot of info from different sources online so I wanted to verify that my understanding of chick development/hatching is correct. I'm not planning to intervene but I do like to know where I'm at in the hatching process. Is the following correct? Inside an egg there are two membranes, one that the shell itself is attached to and one that surrounds the chick and yolk. As the chick develops it's floating in what we know of as the egg white but this begins to evaporate out in the high heat required for incubation, thus increasing the size of the air sac. After the egg white is mostly gone and the chick is in lockdown it "pips internally" meaning that it breaks through the first membrane that encases it and the yolk. It breathes in the air from the air sac until the oxygen is almost depleted, then it goes on to pip externally in an epic quest for more air. Finally it zips around the shell and kicks it's way out. So if I have eggs that are rocking slightly is that typically prior to internal pip and an indication that the chick is positioning itself to puncture the air bubble? And when they are peeping (I hear one chick doing this) has it pipped internally since it's breathing the air between the membranes?