Screw-On Bird Guardian - Birdhouse Protector

Protect your bird's house from the reach of blue jays, crows, grackles, squirrels, cats, raccoons and more! Provides year-round safe housing for:BluebirdsChickadeesNuthatchesSwallowsTitmiceDowny WoodpeckersWrens Easily attaches to your birdhouse with 3 enclosed screws to protect nesting songbirds, eggs, and nestlings from the reach of harm.  The little ladder at the base of the unit helps birds access their roost.Fits any 1- to 1 1/2-inch opening. Note: These guards will not deter invasive house sparrows. For that particular problem we suggest you check out the Sparrow Shield - Invasive House Sparrow Deterrent. Made in the U.S.A.