This happens on a regular basis. But, it's not always the same hens. We have 4 nice nesting boxes that are the same size and have the same straw in them. However, most of my hens want to lay in the 1st box. We have gotten eggs from the 2nd and 3rd box as well. Anyway, on several occasions I will find 2 hens in the box at the same time. I don't actually know if both lay while the other is in there I just keep catching them both in there. Has this ever happened to anyone else. We have had up to 5 eggs in one box. Here is a picture of two hens in the box and two more waiting in line.