For a week or two now some clueless darning-needle type insect has been flying witlessly into my study and out again. Witless house flies who disappear into the house I'm used to; witless wasps eventually learn how to get themselves free from curtains and back outside; but witless whatever-they-ares who keep bumbling in defeat me. Yesterday I came home to a metallic screechy buzz. I figured Witless had got itself caught in one of my tabless Pepsi cans in the recycle bag. But the noise was coming from the shelf behind, from the small wooden shadow box where I keep bibelots like my facsimile Lewis chessman queen and her OMG expression. Specifically from the box with the stone paperweight cat. Close inspection showed that paperweight cat had pooped in its corner: several small slabs of dry grey mud were affixed to the walls and floor.
I must assume the insects have been constructing a nest in my shadow box
ETA: googling suggests I'm dealing with the aptly-named mud dauber, an insect that has crashed at least two aircraft with loss of life to all on board.