Northern Prairie Wildlife Research Center
Wood duck houses must be inspected and refilled each year, preferably just before the ducks arrive in mid-March. Many other creatures will use these boxes, filling them with sticks, leaves, and grass. These unwanted materials, plus the remains of last year's wood duck nests, must be removed. In most cases, complete removal of all the old shavings is not necessary, but some new shavings should be added each year to insure consistent use.