Nyjer feeder with 4 clinging ports and 4 perching ports. Guaranteed squirrel proof! When a squirrel climbs onto the feeder, its weight automatically forces the shroud down, closing the seed ports. Dismantles for easy cleaning. The patented seed tube ventilation system in Squirrel Buster Finch Feeder permits humidity and warm air to escape through vents at the top of the feeder. The escaping air is replaced by fresh air entering through the seed ports. The seed remains fresher and attracts more birds.