Some wasp species establish nests beneath the ground. This article explores which types of wasps use subterranean habitats, how to identify their nests, and the reasons behind this choice. Understanding these aspects can inform how individuals might respond if they encounter a ground wasp nest.
Which Wasps Nest Underground?
Several wasp species commonly construct their nests in the soil. Yellowjackets, a type of social wasp, are frequently found nesting underground in abandoned rodent burrows or other cavities. These wasps, typically about half an inch long with black and yellow bands, form large colonies that can number in the thousands by late summer and early fall.
Cicada killers are another notable group of ground-nesting wasps, recognized for their substantial size, often reaching up to two inches. These solitary wasps, characterized by black bodies with yellow markings and amber wings, excavate tunnels approximately one foot deep to house their offspring and paralyzed cicada prey. Digger wasps, a broad category that includes species like the blue-winged digger wasp, are also solitary. They burrow into dry, sandy soil to create individual nests for their young. Unlike social wasps, solitary species do not form colonies; each female builds and provisions her own nest.
How to Identify a Ground Wasp Nest
Identifying a ground wasp nest involves observing specific visual cues and wasp activity. A common sign is a single entrance hole in the ground, typically ranging from half an inch to an inch and a half in diameter. This opening might be found in lawns, under shrubs, near structures, or in areas with thinning grass. For social wasps like yellowjackets, there is often constant, high traffic of wasps flying in and out of this hole, especially during warmer parts of the day.
The area immediately surrounding the nest entrance may show a pile of kicked-up dirt, resembling a small volcano. In contrast, solitary wasp nests, while also marked by an entrance hole, typically exhibit much less traffic, as only the individual female uses the burrow. Vibrations from activities such as walking or mowing nearby can provoke ground wasps, leading to increased activity around the nest opening.
Why Wasps Build Nests in the Ground
Wasps choose to build their nests underground for several adaptive advantages. The soil provides natural protection against various predators, including birds and mammals, shielding developing larvae and the queen. The subterranean environment also offers insulation, maintaining a more stable temperature compared to surface conditions. This helps protect the nest from temperature extremes, such as intense heat in summer and freezing cold in winter.
Additionally, the ground provides a secure and structurally sound foundation for the nest. The earth’s stability helps prevent the nest from collapsing, ensuring a safe environment for the colony or individual wasp’s offspring to develop. For solitary species, the burrow offers a hidden space where the female can provision her young with paralyzed prey, ensuring their food supply is secure until they mature.
What to Do About Ground Wasp Nests
If a ground wasp nest is discovered, prioritizing safety is important. It is advisable to maintain a safe distance from the nest and avoid disturbing it, as wasps will aggressively defend their home if they feel threatened. Attempting to block the entrance or directly interfere with the nest can provoke a defensive swarm, and unlike bees, many wasp species can sting multiple times.
For social wasps like yellowjackets, particularly if the nest is in a high-traffic area, contacting a professional pest control service is often the recommended course of action. Professionals possess the expertise and equipment to safely and effectively manage these colonies. For solitary wasps, which are generally less aggressive and beneficial as pollinators and pest controllers, a “leave it alone” approach is often appropriate, especially if the nest is in a secluded location. DIY removal attempts for social wasps can be dangerous and may lead to multiple stings or incomplete nest destruction.