Yellow jackets are social insects that build intricate nests to house their colonies. Understanding these structures provides insight into their behavior and lifecycle.
Where Yellow Jackets Build Nests
Yellow jackets construct nests in various environments, adapting their choices based on species and available resources. Many species build nests underground, often utilizing pre-existing cavities like abandoned rodent burrows or natural soil depressions. The entrance to an underground nest typically appears as a single, small hole, with wasps flying in and out. These subterranean nests offer protection from predators and the elements.
While less common, some yellow jacket species build aerial nests. These can be found attached to tree branches, shrubs, or hanging from structures like eaves. The German yellow jacket (Vespula germanica), for example, constructs nests in these elevated locations. Such nests are often visible and appear as gray, football-shaped structures.
Yellow jackets also frequently build nests within human-made structures. These can be located in wall voids, attics, crawlspaces, or under porches and sheds. These hidden locations provide shelter and insulation, but their proximity to human activity can lead to increased encounters. Nesting site choice often depends on factors like food availability, protection, and accessibility.
How Yellow Jacket Nests Are Constructed
Yellow jacket nests are built from a papery material. Wasps create this material by chewing wood fibers and mixing them with saliva. This process results in a durable, carton-like substance that forms the nest’s structure. The paper’s color can vary, ranging from gray to tan, influenced by the type of wood fibers collected.
Nests typically have a spherical or oval shape with a single entrance hole. This outer envelope encloses the internal structure, which consists of multiple horizontal combs. These combs are tiers of hexagonal cells, similar to those in a beehive, connected by small pillars. Larvae develop within these cells, protected by the papery layers. The queen initiates the nest, and as the colony grows, worker wasps continuously expand it by adding more cells and layers.
Nest Lifecycle and Size
Yellow jacket nests generally follow an annual lifecycle in temperate climates. A single queen, having overwintered, starts a new nest in the spring. She lays the first eggs and cares for the initial brood until the first generation of sterile female workers emerges. These workers then take over nest expansion, foraging, and caring for the queen and subsequent larvae.
The colony expands rapidly throughout the summer, with workers continuously adding new cells and layers. The nest reaches its peak size in late summer or early fall, supporting a large population. A mature nest can contain several thousand individuals, with populations ranging from 1,500 to 15,000 wasps, depending on the species. By late autumn, with colder temperatures and the first hard frost, the colony dies off. The nest is then abandoned and not reused the following year, though in warmer climates, some colonies can persist for more than one season and reach significantly larger sizes.