We have been enjoying steady laying from each of our 3 hens - every time in one of the nest boxes made for them...now...in the last several days...things are changing...first...eggs are being laid anywhere...not in the nest boxes, and for 2 days in a row now, one chicken is laying an egg with NO shell... Now, we used to keep them locked up in their coop area while we were at work and let them free range when we got home until they went to roost at night...now we have been leaving the coop door open so they could come and go as they please...is this why they are laying just anywhere? out in the pasture, in the barn, in the horse stalls? We feed either Egglands or Purina layer crumbles, and they get scratch, gravel and I also feed back crushed egg shells for calcium once a week...they also get scraps,...corn, green beans, watermelon..etc...and of course free ranging, they get grasses, bugs, etc...to me, they have a very healthy diet...so what's with the no shell? Still not enough calcium? I am perplexed and need expert advice! Thanks!