Very clever squirrel-proof birdfeeder. The portals close when the weight of the squirrel exceeds the tension of the spring holding up the outer shell of the feeder. However our squirrels can hang upside-down with their back legs gripping the pole and thereby reach into open portals. While there, they can tear the bottom of the inner ring away from the plastic tube, reducing the effectiveness of the portal closing mechanism and enhancing future squirrel dining. We bought suet nuggets coated with red hot pepper said to be undetectable to birds but anathema to mammals. (They sting our sensitive hands.) But apparently some mammals actually prefer spicy food.
