About 1/2 -to 1-inch in length.
Generally small wasps with black and yellow stripes.
Yellow jackets are social insects that live in colonies containing thousands of individuals. Colonies are usually started by a single queen in the early spring, and are very small for the first couple of months. By midsummer, a colony located on or near a house is usually large enough to become a nuisance. These wasps will aggressively attack when their nest is disturbed, and can inflict painful stings. Unlike the honeybee, which stings only one time and then dies, a single yellow jacket can sting many times. Yellow jackets are scavengers and can be beneficial when located in a wooded area or a field. Colonies located in or near a Home, however, can pose a threat to the persons living in the house. When this situation is discovered, the colony or colonies should be eliminated. Because of the danger involved in treating these nests, only a professional should attempt to treat them. Should a colony be discovered, contact your service professional for assistance.
Yellow jackets prefer to locate their nests in the ground, usually in an old rodent burrow or similar hole. This wasp also commonly locates its nest inside the walls of a building by entering through cracks or holes in the outside walls.
The following precautions should be taken to prevent accidental stings:
If yellow jackets are seen entering and exiting a wall, DO NOT plug the hole. You will only force the wasps to find another way out. Sometimes they might actually eat through an interior wall and enter the house.