A wasp that came in through our bedroom window in mid-December: probably a common wasp, Vespula vulgaris (Hymenoptera: Vespidae). A female because if the elongated first anntennal segment. Probably also a worker because it wasn't noticably large, and also because the queens are not usually out and about until the spring-time. There is a very good article on identifying the commoner UK wasps here at Eakring Birds.
Photos taken in Reading, UK, on 2011-12-16.