Anguispira fergusoni is a native eastern North American land snail. On warm and humid days, especially at night, they climb trees probably in search of fungal food. During my 12+ years of wanderings in the park near my house, I've seen them crawling on trees many times, but I had never seen one dormant on a tree until yesterday.
This one, ~12 mm in shell diameter, was on a beech ~65 cm above the ground. The shell was attached to the tree weakly with some dried mucus along the rim of the aperture. After I picked up the shell and looked inside, I saw the snail's foot immediately within the aperture.
There is often something new to be witnessed out there.