fairly new to chickens... About half our eggs come out like they should. The other half have calcium deposits both as bumps on the shell and rings of white. A few have wrinkles in the shell. The fault factors for these problems site, cramped conditions, stress in the flock, or disease. we have 11 hens, they are free range, and the coop has 8 good size nesting boxes, so they shouldn't be cramped. They seem happy, squawking around, burying in the dirt under a tree on a hot day, they never peck at one another, the only stress I can think of is very rarely they run out of water (it happens maybe weekly as it is a kid's chore, all about learning here). That leaves disease, but wouldn't a sick chicken act sick? Our hens are spunky! Sneaking in the house at times and acting like they know they shouldn't be there... Should I be concerned or just let it be and assume our dirt has high calcium content naturally. I don't mind if the shells aren't grade A as long as they are healthy to eat and come from healthy birds Thanks so much!!