Yellow jackets are a familiar sight during warmer months, often mistaken for bees due to their distinct black and yellow stripes. Many people commonly associate these insects with underground nests, imagining them solely residing in subterranean burrows. However, this perception is only partially accurate; numerous yellow jacket species frequently construct their nests in various above-ground locations. Understanding these alternative nesting habits is important for identifying their presence and avoiding potential encounters.
Common Above-Ground Nest Locations
Yellow jackets choose diverse above-ground sites for their nests, often seeking sheltered and protected areas. These aerial nests can be found within the leafy branches of trees and shrubs, where foliage offers concealment. Around human structures, they frequently build nests under eaves, in attics, and within wall voids. Other common spots include crawlspaces, sheds, garages, recycling bins, or hollow logs. These locations provide insulation and protection from environmental elements and predators.
German yellow jackets (Vespula germanica) are known for nesting in wall voids and attics. Nests may also be constructed on the side of a building, under decks, or in dense vegetation. Yellow jackets are adaptable, finding suitable nesting sites in any place where humans live.
Identifying Above-Ground Yellow Jacket Nests
Above-ground yellow jacket nests possess distinct visual and structural characteristics. These nests are constructed from a papery material, created by chewing wood fibers and mixing them with saliva. The resulting pulp forms a smooth, often grayish, wavy exterior. Nests can vary in size, sometimes growing as large as a basketball.
Nests usually have a single entrance hole, often located near the bottom. Inside, the nest contains multiple layers of parallel combs with downward-facing cells, where larvae are reared. Unlike exposed, open-celled nests of paper wasps, yellow jacket nests are enclosed by this paper envelope. A consistent stream of yellow jackets flying in and out of a specific opening or area can indicate a hidden nest.
Factors Influencing Nest Site Selection
Several factors guide yellow jackets in their choice of an above-ground nesting location. Protection from predators is an important consideration, as secluded spots reduce disturbance. Shelter from harsh weather conditions, such as rain and wind, is also important for the colony’s survival and development. These sheltered areas help maintain a stable microclimate within the nest, optimizing temperature and humidity for the developing brood.
Proximity to food sources, including other insects, nectar, and human food waste, influences where queens establish new colonies. While yellow jackets forage up to 1,000 feet from their nests, selecting a site near abundant food reduces energy expenditure for foraging workers. Structural support for the growing nest is another factor, as papery construction requires a stable anchor. Overwintering queens emerge in spring to select these sites, initiating a new nest each year.