It was doing precisley this when I arrived; whilst I watched it for a couple of minutes; during the time it took to get out my camera and shoot this picture; and when I was leaving. Very single-minded critter, obviously. But if you take a look at the Flickr version of this, and zoom in, you’ll notice an eye looking sidelong at me. It knew I was there: it just didn’t care. Guess it likes the strong silent types.