Last year, I had a flock of 8 hens and one rooster, all around two years old. Around August 2013, the hens completely stopped laying. Not a single egg up until I finally gave them away in February 2014. Once the coop was empty, I cleaned it thoroughly, I dug out the old dirt in the pen and replaced it with fresh dirt. I eradicated any mice, and have had no mice sightings since. I hatched a new batch in March, and they started laying around July. They were laying great...until a month ago. Once again, egg production has completely come to a halt. I haven't gotten a single egg since, nor any broken shells or such that would suggest the eggs were being broken and/or eaten. There are no rat snakes and no mice. The person who took my previous flock told me that the hens never started laying again. I have raised chickens my entire life, and this has never happened before, and I've never heard of it happening to anyone else. My breeds are good egg laying breeds. The halt in production has spanned all seasons, so weather changes don't explain it. I've done supplements, vitamins, etc. I am at a total loss. This isn't a case of "low production". It's "NO production"! Has anyone ever heard of this? My hens seem to have become sterile or infertile or whatever you call it.