This morning, in a quiet moment after everyone else had left the house, I was gazing out of the window at the snow when I noticed a squirrel bound along the top of the fence. What struck me was that the squirrel’s springing movements fitted exactly into a pattern of tiny peaks and troughs of snow that lay along its narrow route. It seemed fairly clear that this was a path that the squirrel had trodden before, causing the curious bobbles in the first place. And now it was retracing its steps exactly, leaving the pattern of snow undisturbed.
It would be interesting to know whether it does the same thing again the next time it passes that way. But I do have other things to do than stare out of the window at a garden fence, you know.