I was looking at bird houses an Amazon.com the other day when I ran across this Perky-Pet feeder. The Tufted Titmouse on the left side seems to be having trouble using the feeder.
There are birds that feed while hanging or standing upside down. Take, for instance, the, uh, statue of a nuthatch on this feeder:
Then there are bird feeders designed so the patrons have to hang upside down on them, like this feeder for finches:
The unconventional titmouse gets around. I found him on a Birdscapes feeder, too. Maybe it wishes it was a goldfinch or a nuthatch.
Birdscapes Copper Wild Bird Feeder inset with Perky-Pet close-up