In social wasp colonies there is a queen in the nest laying eggs, and workers who are her daughters foraging for food and defending the nest. Social wasps often build their nests in trees or under building eaves. Some build nests in cavities in the ground. The structures are made from chewed wood pulp. Paper wasp nests consist of a layer of comb cells attached by a stalk to a substrate.
Hornets also make layers of papery combs, but the combs are covered with a papery envelope.
The colonies can get quite large, and their occupants will defend the area near the colony by stinging intruders. Hornets and yellow jackets are more aggressive than are paper wasps. Furthermore, when these wasps believe they are being attacked, they release a chemical odor, an alarm pheromone, that alerts other workers to attack. So it can be painful if you get close to the nest. The best way to discourage social wasps from making a nest is to find it early in the season when there are only a few wasps present.