Wood Predator Guard, 3" dia. holeBlock squirrels and raccoons from reaching into your existing bird houses with this Coveside Wood Predator Guard. Wooden square has a 3 diameter, center hole, for aligning with the opening of your existing woodpecker or owl house. Four predrilled, smaller holes in the corners allow this item to be screwed directly onto your existing bird house. 0. 75" thick wood extends the entry, so predators cannot reach into the shelter and steal eggs or harm