Comfortable nesting boxes encourage egg production. Chickens will hold back or lay outside of the boxes if the box size and nesting material is inadequate. Observe your chickens and make adjustments to the boxes as necessary. Egg laying is a private affair and your boxes must provide a safe and isolated position for egg laying.
Nesting Box Size
Box size is not an exact science and many chicken owners have a personal preference. The minimum standard is 1-foot depth, width and height. Wooden nesting boxes are typical but many different materials work for boxes. Milk crates, bowls, metal pails and any container that will hold nesting materials while providing space for the hen is acceptable.
Numerous bedding options are available. Experiment with different bedding to find the best material. Straw is a common choice but it lacks softness. Many chickens will kick the straw out of the box before laying eggs. If straw does not work, try pine or cedar shavings. The shavings are soft and easy for the chicken to manipulate. Shredded newspaper is an affordable option that works well for many chicken owners. Grass hay is also soft and provides a nice nesting material.
Do not use grass clippings from an area that receives pesticides and chemical applications. The toxic chemicals are bad for the health of your chickens.
Place your nesting boxes in an area that is accessible, safe and somewhat private. Coops often have boxes integrated into the design and chickens will enter the nesting area directly from the coop. Hanging boxes on the outside of your coop works well but they must have protection against the elements. Wet bedding attracts flies and creates a poor nesting environment. Utilize an area that is quiet and isolated from the social and forage areas. The isolation provides the hens with comfort as they lay without worrying about predation or pecking from other hens and roosters.
Replace the nesting materials on a weekly basis. Chickens will defecate in the boxes and you must keep them clean. Wipe the boxes down with a wet rag on a regular basis as well. Cleaning metal and plastic is easy with a rag. Wood is absorbent and requires more scrubbing to clean the surface.