I have discovered Gold finches are evil also. They are wasting feed. I had to get a new feeder for them. They broke the last one...The little Buggars!!!
I got one of them with the tray under it to catch what they drop, so you can tell if they are wasting feed....Well they are!
Look at the mounds of feed they have thrown out and onto the ground, that the tray catches!
I might just let them starve if they do not get some table manners!