A little background first.....I have 4 RIR's that are about 20 months old. I got them last April and they were all already laying. This is my first winter with them and the egg laying did cut back to about half (2 eggs or less ) per day. They all appear healthy. I have noticed that in the last 2 weeks I have been getting what appears to be one shell-less egg but only during the night while they are roosting...not in the hen boxes. I am hoping that this is just an adjustment to going back to laying again but have noticed that I am seeing this every few days. Hope someone can give me some insight. I forgot to mention that i do have a continual source of crushed oyster shell. I am trying not to panic as I have grown so attached to these girls.