When candling eggs, how can you tell if the air cell has been pipped?

[Jo1313]

When candling my duck egg, i recently saw that the shape and size of the air cell had changed from being straight across to slightly tilting and slightly larger - does this signal that the chick has broken into the air cell?

 

[Littleturkey123]

No, this is quite normal. As you progress through incubation the air cell changes from small to big to being angled, if it is near hatch time and you see a beak inside the air sac then it has pipped.
Good luck,
L