I've never seen one do this, and was amazed to learn that she had apparently buried a nut and was checking to make sure that it hadn't been stolen. The last motion she makes with her hands is her fluffing the grass so it won't appear to be disturbed around it. Someone in the thread said that if a squirrel knows they're being watched by another squirrel, they will do the same thing but in a spot where nothing is buried. They are smart little guys 
