I have six hens who have been laying now for over a month. They NEVER lay in their boxes. They don't seen to care that much about where they lay. One laid an egg right in the middle of our yard while they were free ranging. They do, however, prefer to lay in the corner where the water is. Their laying boxes are about 2 ft off the ground. I also installed their roost which is maybe a little over 4 ft high. They have more than enough space on there but aren't using it. How do I get them to start using them?