1-1/2" hole for Eastern Bluebirds and tree swallows.
These birdhouses are made from a unique blend of 75% pine sawdust, burnt clay and other natural materials, formed and baked to provide a nesting home for birds that is healthy for them and which will last for 20 years or more in your garden. This remarkable material actually "breathes" like wood. Yet it is completely rot proof and the non-toxic brown paint on the roof and sides sheds water. Resistant to damage by squirrels and raccoons.