I have chickens (silver-laced wyandotte) that have been very regular about laying up until a few months ago. I determined my first problem was a snake as the eggs were gone, including the shell, but no chicken missing. Also, there was yolk on one of the fake eggs I put in for a deterrence. One of the fake eggs came up missing but none after that. A couple of times I noticed the hens were more anxious than normal and they didn't want to go to their regular nests. I made new nests in a slightly different location and put eggs in it. Since it's gotten colder, the introduced eggs have stayed where I put them and none have come up missing yet. The weather has since gotten too cold for snakes so I set out a live animal trap, rat trap and a mouse trap. Except for the rat trap, the bait has gone undisturbed. I think the mice ate the bait from the rat trap and were too light to trigger it. I feed and water my chickens as I always have and before now have not had a problem like this. They get a laying mixture from the feed store, corn, milo and crushed, baked chicken shells. I augment this with whatever vegetable matter I have left over in the kitchen. They recently molted but this problem started much earlier than their molt. They seem to be contented and comfortable. No anxiety now. Any suggestions?