Depends on the breed some stop with cold weather and some keep laying in cold weather, how many roosters do you have. Stressed chickens will not lay eggs. If something is bothering them or they are scared they will stop laying. Are kids bugging them, cats, dogs, other types of animals. One year we had a strange dog show up and he chases the chickens and killed a couple and all my hens stopped laying cold turkey. It was January and they started again when it started to warm up. But they have not done it since. they lay all though winter and I live in MN, when they stop they are either molting or they are stressed over something. To many hens in a small area will cause stress too and they will stop laying. I use to think the more chickens you have the more eggs you have not true. I have 7 year old chickens that are still laying eggs