These wasps can be black and yellow or black and white in color. Yellow jackets are 5/8 to 1 inch long and have a thin waist. They are one of the most aggressive wasps in defending their nests. Like all wasps, yellow jackets prey on a variety of insects and other arthropods. Yellow jackets will also forage on foods people eat, especially sweets and meats. The yellow jacket colony will remain active for only one summer, after which the queens will fly away to start another colony.
Yellow jackets usually nest in the ground, but will also nest in railroad ties, wall voids, and other above ground locations. In the spring, most yellow jackets will feed on insects. In the fall, wasp colonies are at their largest size, and foraging workers may be a serious nuisance as they search for food. For most people a sting is painful but temporary. However, an allergic individual may have a serious reaction requiring medical treatment.