In Fauna Britannica, Stefan Buczacki describes this butterfly’s ragged outline as being the ‘shape of a fallen leaf’ and its colours, too, are quite autumnal. This is the most grammatically correct of Britain’s butterflies, the Comma, Polygonia c-album.
Though I have no personal experience of this, the Comma is, apparently, one of the three butterflies most likely to be found hibernating in sheds and outhouses – the other two are the Small tortoiseshell and the Peacock. Adult Commas can usually be seen flying between March and September so maybe these ones I’ve seen recently were having their last feeds before looking for a cosy spot to snooze away the cold months of winter. If I had a shed, they’d be most welcome.