Most nest boxes have been made out of wood or metal, each having certain advantages and disadvantages. The wood nest box is sometimes more readily accepted by wood ducks, but the metal nest box can provide a safer nest site. While the metal box tends to be predator proof, additional measures will need to be taken to deter predation of nests in wooden boxes. The wood nest box is easy to build, while sheet metal required to build the metal nest box can be hard to work with and may require special tools. The wood nest box generally blends in well with the natural landscape.
Squirrels tend to avoid metal boxes while both squirrels and starlings prefer to nest in wood boxes.
The metal nest boxes will last 10 to 15 years while the life-span of the wood nest box may be considerably shorter depending on such factors as types of wood used, quality of construction and weather. Whether you use wood or metal to build your nest box, you must remember that ducks do not carry nest material to the nest. Therefore, suitable nesting materials such as coarse sawdust, wood chips, or shavings must be provided in the bottom of every nest box. It is important to include some wood chips or shavings since sawdust alone tends to pack. Even the best built nest boxes will not be used if nesting material is not provided.