The Squirrel Buster Mini is guaranteed to be squirrel proof * Openings in the bottom of the metal mesh shroud are aligned with the seed tray and allow birds easy access to the seed * When a squirrel climbs onto the feeder, its weight automatically forces the shroud down, closing access to the seed tray * Seed ports have perches for the perching birds but the metal mesh shroud also offers a large clinging area * Patented Seed Tube Ventilation System in Squirrel Buster Mini permits humidity and hot air to escape through vents at the top of the feeder