During my post-lunch walk today, I found some dormant snails under a rotting piece of plywood. All I can tell about their identity is that they are a species of Triodopsis, but figuring out the exact species—usually from the subtle differences in the positions of the apertural teeth—will take more effort than I can put in now.
Every single one of the 8 adult snails had its aperture covered with a thin membrane-like layer of dried slime and was partially buried in soil with its umbilicus up, which is the preferred position of snails hibernating in soil (I don't know why).
I decided that it was a good idea to mark the snails* so that I can check up on them throughout the year. Come to think of it, I should go back there tomorrow and look for some juveniles to mark. That way I can get an idea of how long they live. The beginnings of a little project? Maybe.
Here are the marked snails before I turned them over and placed them in their little depressions in soil under the plywood.
*Behind their lips with red ink from a Staedtler Lumocolor pen that is, according to its labeling, lightfast and waterproof. We shall see.