Following taxonomic and morphological descriptions, the behaviour, colonial dynamics, social communication and especially the remarkably diverse nests of wasps are discussed. Compared to the better-known species of paper wasps, hornets and yellow jackets, the hover wasps show various peculiarities, such as characteristics of immature brood rearing, nest defence and mating systems. The nest architecture probably presents the most variable solutions in social wasps and is characterized by an astonishing level of camouflage, making these insects an interesting example of special adaptation to forest environments.