BestNest Woodlink Bluebird House Package with Poles Provide shelter to four beautiful bluebird families with the Woodlink Bluebird Houses and Poles. Each of the four Woodlink Bluebird Houses is crafted from durable, 0.75 thick cedar. The included Coveside Blowfly Inhibitor Screens help nests stay safe from parasites. Use the included Coveside Slate Hole Protectors to surround each entry, keeping other birds from enlarging them. Hardy poles include mounting brackets and ground sleeves for versatility