My girls began laying recently and their egg shells are rock hard. Like, I've read of people have the opposite problem, and I guess it really isn't a big problem I would just like to know what would be causing it? I have started giving them layer feed, but even before then the eggs were ultra strong. It seems to be most all of my eggs, not just from one specific breed. I have a very mixed flock. Well it's not a real emergency or anything I was just wondering what you guys think. Thanks.