My husband had a BIRD CONDO. This was some contraption he set up himself on a big pole 15' high. There were many feeders hanging off branches. He loves finches so much, and they loved him. When he would change the feeders, they would literally be all over him, totally unafraid.
The squirrels will figure out the best of blocks...believe me, they are not dumb. I've watched one literally fly through the air to land where they couldn't climb (sort of like spiderman). I've watched two of them messing with a feeder so much, the whole thing came down. We had barriers on the top, barriers on the bottom, and every barrier on the internet on each feeder.
Then came the rats......Yikes, the whole thing had to go. Such a big bummer.