We've had a big chicken problem lately; not only have we suffered through something like worms, and Cocci earlier this year, and lost half of my babies, but now our egg production (twenty a day at least) has dropped from 0-1 eggs a day. We have at least 40 laying hens. I've tried everything; worming them, treating them for Cocci, feeding them extra, checking to make sure they're not overheated... They get clean, cold water 4 times a day, and we've even added vitamins/electrolytes and vinegar to their water in turn, with no success. Oyster shells, scratch grain, laying pellets, chick food, house scraps, fruit (in abundance! They're getting into the peach/plum/apple trees) insects, grass, and whatever else they free-range is their diet. These birds have run of two coops, pens, and a two-acre fenced in yard. They have plenty of waterers, and most also get out of the lot and roam our thirty acres of pasture/woodland. Still no eggs! They don't seem sick at all; ALL birds act completely normal: but no eggs. They're not thin, they're not pale in the face, they're not staggering or limping, or even hanging around in the shade or around the coops more then normal. I thought, maybe they're laying out in the woods? I don't believe that's the case; to allow full-grown hens to get out of the lot I have to open a door. The babies can slip under the fence, but the hens have to go through the door. Egg production had dropped during a streak of days inside the lot! Not free-ranging outside. And now that I've free-ranged them more, there has been no stir in egg production. I thought, maybe a snake or other predator? I go out several times a day (and night) and scan the coops, the lot, and the area around. No feathers, broken eggs, shock in chickens, anything. It's so frustrating, and weird! Any help would be greatly appreciated!!