My hens have just started laying and will not use the nesting boxes I've had set up for weeks. I have placed golf balls in them and even left a real egg in one while a hen was looking to make her nest to lay. She also laid on the ground. I have wooden boxes and plastic milk crates, both filled with wood shavings. What can I do different? I have placed the boxes on the ground where they have laid. I have placed some about 8 to 10 inches off the ground and have some 3 to 4 feet off the ground. All are below the roosting poles. I guess they just like the ground.