Speaking from anthropological point of view, I lean against calling any animal stupid. I'm a proponent of believing they're wired to react a certain way to a given stimulus. A lot of people think chickens are stupid, but they're not. If you watch them carefully long enough, you start...
After seeing broken, empty shells in the coop, I decided to research possible solutions. The best one I found was on youtube that uses egg box design rather than darkness, mustard, etc. The egg box is altered by tilting it forward, then a piece of hardware cloth is formed into a horizontal "u"...