Natural materials help keep birds safe from predators as they blend in with surrounding areas and do not attract unwanted attention. Birds desire a house made of rough material because rough surfaces make entering and exiting easier. Reed grass is resistant to premature decay. Roosting pockets are especially beneficial to non-migrating songbirds during the winter months. They provide much needed refuge from harsh storms, wind, freezing rain, heavy-snow and the bitter cold. Reed grass construction. Natural ventilation and drainage, blends into surroundings. Loved by a wide variety of songbirds.