My chickens are about a year old. I have three coops/runs - one with welsummers, one with buffs, and one with sex links. Four in each coop, and the coop/runs are quite large, could put probably eight more birds in each area. They all started laying last year in August and then stopped for the winter. I did not provide supplemental light. They are STILL not laying this spring. I feel like they really should be! They are eating 16% layer mash, lots of kitchen scraps, and occasionally boiled mashed egg. Not a single egg!! What is going on? What should I check for??