Adult workers are about 3/8-5/8 inches long with the queen about 25% longer. The abdomen usually banded with yellow and black and may be marked with red. The wings will be folded along the side of the body.
Yellowjackets will usually nest in the ground in places where vegetation is bare. If there is vegetation around nest site they will clear the area around the entrance. There are nest entrance guards to protect the colony. Yellowjackets are very slow to sting unless the nest entrance is approached and then they are quite aggressive. They can sting over and over again with any harm done to themselves. Those nesting in or on buildings are only a problem when the nest is located near human activity. Hibernating queens may enter the living space during the winter seeking warmth, or in the spring when they are looking for a nest site or just trying to get back outside.
Yellowjackets are social insects and live in nests. The adults are represented by the workers which are sterile females, queens and males which come from unfertilized eggs and usually appear in late summer.
Only the inseminated queens hibernate and do so in sheltered places. When spring arrives, she uses chewed-up cellulose material to build up a paper carton nest of a few cells. It will eventually hold 30-55 cells covered by a paper envelope. One egg is laid in each cell and the queen feeds the developing larvae arthropod protein material and nectar. After 30 days, the first 5 to 7 workers emerge and shortly thereafter take over all the work except egg laying. The nest will, at sometime, consist of a number of rounded paper combs which are open ventrally and attached one below another. They are usually covered with a many-layered paper envelope. Nest sizes can vary from 300 to 120,000 cells. The average cell count is between 2,000 to 6,000 and usually consist of 1,000 to 4,000 workers at its peak. Later in the season, larger reproductive cells are built in which queens will be reared; males are usually reared in old worker cells. The colony then goes down hill at this point. The newly emerged queens and males leave the nest and mate. Only the pregnant queens hibernate and survive the winter. The original queen, workers and males all die.
Vespula vulgaris Linaeus