‘There’s a flat rat under the mat!’ I shrieked, and wondered whether that was the sort of jaunty phrase that could be used for elocution lessons. I had lifted this mat by the main staircase to hoover the floor beneath it and there it was, a perfectly flat rat in the shape of a cartoon dead rat beneath this mat. I began laughing uncontrollably, because if you’ve ever seen a flat rat under a mat you will know that it is intrinsically funny, whatever your views on rats.