We have two hens; big momma is perhaps a year old, little momma is 8 months old. In the coop we set up four nesting boxes with a plastic egg in each one, but they always use the same nest to lay. A couple times we've rearranged things, and they switched nest, but still shared the same one. We've moved the plastic eggs out of their nest of choice, so they see more options in the other nests, but that didn't do anything. They don't lay at the same time, so I haven't seen two of them in there at once. Is little momma just following the lessons that big momma teaches her? Is this common?