I had to be gone all day so my poor ducks were left in their safe, secure pen all day and never got out at all. My hubby was working out of town and high winds and rain were expected so this was the best - but they don't believe me. So this morning I go to let them out and collect the two eggs I expected. Betsy must have been pacing in and out of the house (or maybe I can blame Mikey who normally doesn't step into it) and the eggs had duck tracks on them. Dirty eggs get set aside for our use instead of sold and for some reason I decided to wash them. I am used to not seeing any air sack at all in Betsy's eggs and these had TWO! Betsy's eggs are so round that telling the pointy end from the round end is an exercise of frustration. Each had a noticeable small air sack on one end and what appears to be a very large one on the other. It's just Betsy, and I take the egg out every day. She marches in, sits in her "nest" (a deep hole in the straw), shoves the egg even further under the straw, maybe nibbles on the easy to reach feed dish, then walks away never looking back. All this happens between 3am and 5am every night like clockwork. I didn't crack the eggs, but the flashlight was pretty clear that it is something different that looks like a large air sack. I need to know if it is some time of stress I need to deal with or if it is just something that happens once in a while.