What Dogs Do

For day 48 of my project 365 I  thought I'd have a little fun with the photographs title. The answer to the title is the subject of the photograph: The answer is pretty easy, It's bark on a tree (I think an Oak). The thing that is interesting about this photo is the tiny amount of green moss that's on the bark(near the center). I barely saw it at 1st but now that I noticed it I can't NOT see it :-)