I have a black laced Wyandotte that is approximately 16 months old. She as two other chickens in her flock and they are free range, with layer crumbles, oyster shells and water available at all times. She quit laying all together about a month ago. I thought that she was molting, but then about 2 wks ago, she started laying what I call rubber eggs. Basically no shell, just the membrane. She seems to feel just fine, goes about her daily hunting and pecking and doesn't appear to be underweight or suffering in any way. These are my first chickens so I don't know if I should be doing something for her. The other two are laying just fine.