Boiled eggs like rubber and sometimes shell half empty

[Chicked James]

I have 4 3 year old chickens all different breeds. There was no problems till about a month ago, I boiled 12 eggs and when I peeled them they were like rubber and about half of them were only half full with the yokes all at the bottom. They were not over cooked, could it be something in their diet.

 

[PirateGirl]

How old were the eggs?

Old eggs as well as thin shelled/porous eggs will lose liquid (evaporation) through the shell over time and have more air in them.

 

[woodmort]

How old were the eggs?

Old eggs as well as thin shelled/porous eggs will lose liquid (evaporation) through the shell over time and have more air in them.

My thoughts exactly. Where the eggs collected every day or did you find them hidden some place?