It is about 12 mm long and has alternating yellow and black markings on the abdomen. The wasp is very aggressive in defending itself or the nest. The stinger is not barbed, so the wasp can sting repeatedly. The yellow jacket nest can be quite large for some colonies. It is made of a papery material. Inside, the new nest has layers of combs to raise the brood. Some nests are aerial, but most often nests are subterranean or both aerial and subterranean. People are usually stung when they step into or disturb a nest.