Baldfaced hornets are large (3/4 inch long) and black with white markings, particularly on the front of the head and the tip of the abdomen. They construct an inverted, pear-shaped, enclosed paper carton nest which can be up to 3 feet long. The grayish brown nest has two to four horizontally arranged combs and an entrance hole at the bottom. Baldfaced hornets are social insects. The mature colony consists of a queen, 200 to 400 winged infertile female workers, brood (eggs, larvae and pupae) and, in late summer, males and reproductive females. Larvae are legless and maggot-like, and develop through several stages (instars) before pupating. belongs to the yellow jacket family (Vespidae). Its sting can be intensely painful.
Nests usually hang in trees, but may be attached to the sides of buildings. Nests are made of "paper", which is made from chewed weathered wood from old boards, fences or siding by workers. Mated female wasps or queens overwinter in protected habitats such as cracks and crevices, and begin a new colony the following spring.
This was found at the start of hibernation, and after was safely put back under the rotting wood where it was found.