A TIME-HONORED FEEDER BIRDS CAN ALWAYS COUNT ON TRULY SQUIRREL-PROOF: Openings in the shroud align with the feeding ports, providing birds access to the food. When a squirrel climbs onto the feeder, its weight automatically forces the shroud down, closing access to the ports. Squirrels and some large birds are foiled but not harmed in any way. PAYS FOR ITSELF IN SAVED SEED: Squirrels can no longer steal your wild bird seed. Over a short period of time this adds up to substantial savings that will pay for the purchase of your feeder. RECOMMENDED BIRD FOOD: Black oil sunflower or/and safflower seeds. GREAT FOR BIRDWATCHING: Keep an eye out for all the fun birds you'll meet at this feeder! FOR BOTH PERCHING & CLINGING BIRDS: The seed ports have perches for perching birds and the wire shroud provides a surface area for clinging birds. This increases your bird traffic.