My ten chicks are laying at 6 mos. Recently I've noticed a few eggs are showing slight Crack lines ... Though not piercing shell. One had a tiny hole in one end. I put plenty of growth/laying pellets out as well as scratch grain and they get free range time of about 6 hrs per day. They look healthy, but don't seem to eat much of the laying pellets. What will make their shells stronger. This is my first batch to raise and I love having them around. They are pets. Thanks for any advice!