Recycled Plastic Wren House doesn't crack, peel, chip, rot or warp. Songbird Essentials plastic products utilize recycled plastic which is composed of post-consumer waste and packaging. Choose the product that lasts forever, keeps plastic out of landfills, and prevents deforestation. Attracts smaller birds such as Wrens and Chickadees. Hinged roof allows easy opening for viewing and cleaning. Plenty of ventilation and drainage. Small hole size excludes Sparrows and Starlings Entrance hole measures 1 1/8 in.