https://dxnest.com/yen-tho/
A duck nesting box provides a home for female wood ducks and other cavity-nesting species in wetlands where natural cavities are scarce. Wood ducks prefer natural tree holes, but in the absence of such sites they will use man-made structures such as abandoned woodpecker holes or natural voids in trees resulting from fire, lightning or disease. Deployment of large numbers of artificial nesting cavities can significantly augment local wood duck populations and enhance the success of wild duck management programs in areas where natural cavities are unavailable.