We have two squirrel proof feeders. Never saw a chipmunk climb up the pole. The Chipmunks here gather seeds the birds drop or throw out.
We have to try to prevent raccoons from taking ours down. They are strong metal feeders but the raccoons can undo bungee cords used to keep them attached to the feeders and hangar attached to a 4x4".
I would get a heavy wire to attach it.
I guess they are hungry enough to try anything to get at the food.