I have pole mounted feeders out in the open. For others, I use a 10ft section of 1in. black steel pipe, suspended horizontally between 2 trees or poles so that it would have to be a 5ft jump to the feeder. I then put a baffle over the feeder so they can't get on it from the top. All of this is 6 feet off the ground.
That worked until I woke up in the middle of the night to see a raccoon hanging by his back toes, looking like a 50lb bat, taking out tools from his tool belt and meticulously dismantling the feeder. I think that's what I saw, I was on meds at the time. But, my having to run the pack of jackal squirrels off that were feasting on the downed feeder and rebuild everything the next morning seemed to confirm it.
I can't wait until flying squirrels adapt to birdfeeders. They don't weigh much and they could hit the feeders from anywhere. It'll be cool...sorta...and reeally noisy...

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It seems that the more I know, the more questions I have.