I have four, 8 month old Brahmas that have all started laying - , one started at six months, now the others have caught up. Unfortunately only two use a nesting box! I have two boxes, but they seem to favor one. So I get two eggs in the box and and I find two eggs left in the sand outside the boxes. They seem to lay at different times throughout the day, so I don't think they vying for the one favorite box. Any suggestions for my 'sand layers'?'