We've (ok, I've) still not fitted a cat flap for Cookie and Mocha, as they seem quite content with their personalised aperture opening service. As a system, it does have the advantage of taking into account which direction the weather is galloping in from, thereby giving a much pleasanter feline experience via whichever door or window opens onto the leeside of the house. In turn, we have become used to checking said aperture for an irate bundle of fur, silently miaow-ing at the double glazing. "Irate" because we're never, ever quick enough to respond, and "silently" because of the sound insulating properties of modern doors and windows. All these decades later, I still find the silence of double glazing a little off-putting, having grown up in a house which had such thin panes of single glazing and so many draughts that it often felt like there weren't any windows. However, my ears were certainly attuned to any and every bird sound outside, whether i...