re: Wood Duck Boxes

An old timer in Lafayette area who I've putchased a few boxes from has been making them for years. He recommends to mount them on 4"x4" square posts. Claims the snakes will not climb a square post that thick. And all of mine are on land just near water, but not below many trees or anything that predators could have easy access to.
Also, if you notice in the plans, there is a pretty decent overhang above the entry hole. The guy says this prevents raccoons from standing on the top and being able to reach into the hole and down into the bottom of the box where the hen or her eggs would be. Definitely put the chicken wire on the inside lining the panel below the hole for the chicks to latch onto and make their way out.