I am busy painting and fixing up the tiny courtyard outside my back door and I removed an old broom cupboard that was mounted on the wall. Apart from a mess pigeon nest and bird turds all over the top of the cupboard there were some tiny wasp nests.
The little row of mud condos behind the cupboard were probably made by a keyhole wasp, a small, solitary spider-hunting species which gets its name from its habit of building nests in small holes, natural or man-made. These look to be old and the young wasps have grown up and abandoned their nursery. They were quite cute and even thopugh they are empty I wish it wasn't necessary to scrape them off the wall.
The inhabitants of this nest are not so cute: whichever paper wasp started building this must have decided that the location wasn't to her liking as this is just a tiny starter nest. Paper wasps are social insects, meaning that they live in groups and a good size nest contains dozens of cells and can easily be home to a colony of 20 or 30 aggressive adults. Not what you want to have living right outside the back door. They would be hibernating in a crack somewhere at this time of the year but there are a number of their nests around the property. I leave the nests alone, so long as they aren't too near the house as I am highly allergic to wasp stings.