I have three hens that were giving to me by in laws and two of them stopped laying, I know they were not young hens to begin with, but I don't know their age? I've tried light and treats anything to make them happy, I have checked them for health issues and they are kept clean no mites, or parasites. I am starting to think it is an age issue. What do I do with these old gals that are eating but not producing? We are not attached to them in any way and honestly the one is a white leghorn the other a barred rock, so I am quite surprised to see the leghorn not laying. Suggestions??