A spell of wet weather, so I shall compose a flurry of blogs!
Some animals and birds spend a lot of time on vertical surfaces, so they are specially equipped to find footholds just about anywhere. This squirrel is using its front paws to eat upside down on the hickory trunk, so it is only using its back feet and its body to hold on to the rough bark.
Nuthatches are good at this too, and tend to do their scavenging and eating head down.
They have very long claws which seek out tiny cracks in the bark.
Finally, this woodpecker has claws like grappling hooks, seen in closeup on the bird feeder.
On the tree trunk, it uses them to seek out tiny holes and crevices, to make itself truly stable before it begins to hammer away. Mountaineers, watch and learn.