Sometimes I have other, unprintable, names for these guys!! I do enjoy them and feed them, but they are so ingenious that they've been able to get around every impediment I've put in their way to keep some of the feeders just for birds. As for squirrel-proof feeders, they've been able to make short work of all of them! I hoped that by providing them with three feeders, they'd leave the other 3 for the birds, but they want it all! Having said that, I really like them and they are so clever and engaging and fun to watch.