In danger of hijacking someone else's thread, so figured I'd start this one... Okay, so who is tracing their air cells before lockdown? I started doing this last summer, and found out some really cool stuff--like where the pips usually occur on the egg, and which direction they zip, and so on. I now ALWAYS trace the air cell. I used to trace it at each candling, so I could watch it grow, but that's gotten to be too much now that I'm hatching 20 eggs every two weeks. Now I just do it at lockdown. And now I've added something new, starting with my most recent hatch: I traced a small circle where I could see the duck's bill sticking into the air cell. Of course this only works if they've pipped internally prior to lockdown, but I did learn something cool from it--I can predict even more accurately where they are going to pip, based on where their bill is after internal pip. I'll take pictures next time, but wanted to share that and see if anyone else wanted to try it. I no longer have to wonder where the pipping will occur! Oh, and does anyone have birds that zip clockwise? Mine ALWAYS zip counterclockwise. And furthermore, even the batch of quail I hatched recently zipped counterclockwise. Is that true of all birds?