They make these things called Goldfinch feeders that are like a sock in character, however, if you don't know what you are getting you will get one where the seeds fall through the holes as you fill it. The birds land on it and their movement knocks the seed out. So, what you do is invest in a tube type feeder where there is a tiny hole at each perch. The seed still comes out but in very small amounts. Another advantage is that the seed stays dry during rains where it will get very wet in the sock. I like this one so much I took a picture of it.