I do like the baby monitor or should I say chicken monitor idea and now Jim has the great idea with the flour. If I was you I would get up super early in the morning and be waiting with my AR-15. What ever it was that had you chickens to scared to come to eat, it must of been bad. I would rather do that then go out and find one or more dead birds. So many times we don't get any warning there is a problem. You should be happy you got a warning before anything happened so that you can fix the problem. Good luck and let us know what happens.