It is more efficient to build trapnests in multiple units rather than singly. And like any nestboxes for chickens, they should be mounted on the wall. Not only do wall-mounted nestboxes save on floor space and keep eggs cleaner, they help prevent egg-eating: If the cock of the flock takes a curious peck at an egg in a floor-level nest and cracks the shell, the hens as well start to peck at the crack—and discover there’s something good to eat inside. As one hen learns from another, the epidemic of egg-eating can be costly and very difficult to eradicate.