Yellow jackets are a common sight during warmer months, recognized by their distinct black and yellow markings. These social insects are known for aggressive behavior, particularly when their nests are disturbed. While some species build visible nests, many yellow jackets construct their homes hidden beneath the ground.
Anatomy of an Underground Nest
Yellow jacket nests found underground can vary in depth, typically ranging from a few inches to over a foot below the surface. Some nests, particularly those utilizing existing deep burrows, have been observed at depths of up to four feet. These subterranean structures are initially started by a single queen in the spring, who begins building a small paper nest. As the colony grows throughout the summer, the nest expands into multiple horizontal layers of comb cells, all encased within a protective paper envelope.
The material used to construct these nests is a unique paper-like substance, created by workers chewing wood fibers and mixing them with their saliva. While the internal structure can be quite large, the visible entrance to an underground nest is usually a small, inconspicuous hole, often no larger than a nickel. By late summer, a mature yellow jacket nest can reach a considerable size, often comparable to a basketball or even a volleyball, and may house thousands of individual wasps.
Factors Influencing Nest Location and Depth
Yellow jackets exhibit specific preferences when selecting a site for their underground nests, which in turn influences the nest’s depth. They frequently choose abandoned rodent burrows, such as gopher or rabbit holes, as these provide a pre-existing cavity to build within. Beyond old burrows, they are opportunistic and will utilize any suitable existing cavity, including those formed by tree roots or cracks in foundations.
The type of soil also plays a role, with yellow jackets generally preferring soft, well-drained ground that allows for easier excavation and expansion of the nest. They are capable of enlarging these existing cavities using their strong mandibles. Nests are often located in hidden spots, such as under logs, rocks, or dense vegetation, which offers both protection from the elements and concealment from potential threats. These environmental factors contribute to the variability in nest depth.
Identifying and Safely Approaching a Nest
Identifying an active yellow jacket nest entrance requires careful observation, as the entry point can be quite subtle. Look for a small, often camouflaged hole in the ground where yellow jackets are consistently flying in and out, creating what appears to be a busy flight path. This activity tends to be most pronounced during the late summer and fall as colonies reach their peak size. If you suspect a nest, you might also observe yellow jackets flying in a straight line from a food source back to their hidden home.
Approaching a yellow jacket nest demands caution due to their highly defensive nature. It is advisable to maintain a distance of at least 10 to 15 feet from any suspected nest entrance to avoid provoking the colony. Disturbing the area around a nest, even through vibrations from footsteps or lawn equipment, can trigger an aggressive response. Unlike honeybees, yellow jackets can sting multiple times, and they release an alarm pheromone when threatened, which can prompt other wasps to join the attack. For these reasons, attempting to remove an underground nest yourself is not recommended; instead, it is safest to contact a professional pest control service.