This grey squirrel was vigorously rubbing his face along the branches of this serviceberry in the BYG. I watched for some time as he rubbed and rubbed in this position, then sat up and wiped his face with his paws over and over (like a cat), and then proceeded to do a full-body scoot along another branch, leading with his face and ending up splayed along the branch. When I saw the photos at home I realized that his face was very wet. I have no idea if he was trying to rub off whatever it was, but his actions seemed to suggest this. I remember a year or two ago, seeing a red squirrel with a very wet, almost sticky looking face, just as this guy has. Perhaps it got into something like oil, or maybe the warmth has caused some tree sap to flow, though I didn't notice any. Whatever it was, it seemed to be disturbing the poor guy quite a lot.