Paper wasps, belonging to the genus Polistes, are common social insects found across North America. They are generally non-aggressive when foraging away from their nest. They sting almost exclusively for defensive reasons, focusing primarily on hunting pests like caterpillars and flies for their developing young.
Identifying Paper Wasps and Their Nests
Paper wasps are recognized by their slender bodies, narrow waists, and long legs that trail or “dangle” visibly beneath them when they fly. They measure between 0.75 to 1.25 inches in length. Their coloration typically involves shades of brown, black, and yellow markings.
The most distinctive feature is the nest, which gives the insect its name. Paper wasps construct their homes from chewed wood fibers and saliva, resulting in a gray, papery texture. The nest is characteristically umbrella-shaped, attached by a single stalk, and has open, visible hexagonal cells. These open-comb nests are commonly found in sheltered, protected locations, such as under eaves, porch ceilings, window frames, and beneath decks.
The Context of Defensive Stinging
Paper wasps are classified as defensive stingers, meaning they only initiate an attack when they perceive a direct threat to their colony. They are not predatory toward humans and do not instinctively swarm like yellow jackets. The primary trigger for stinging is an encroachment on the nest’s immediate territory.
A sting may occur if a person accidentally brushes against the nest or causes vibrations to the structure it is attached to, such as a railing or eave. This physical disturbance is interpreted as an attack, prompting the wasps to defend their young and queen. When a wasp stings, it releases an alarm pheromone, a chemical signal that quickly alerts other colony members to the threat, potentially resulting in multiple stings.
The likelihood of a defensive reaction changes dramatically throughout the year, corresponding to the colony’s life cycle. Aggressiveness is lowest in the spring when the queen is establishing a small nest. It increases significantly in late summer and early fall as the colony reaches its maximum size, often housing dozens of workers.
Prevention and Safe Practices
To minimize the risk of a sting, the most effective strategy is to proactively inspect your property for new nests starting in the spring. Early-stage nests are small and easier to manage, often containing only the founding queen. Sealing small cracks, crevices, and entry points on a home’s exterior can deter wasps from choosing a nesting location near human traffic.
During a close encounter, the safest reaction is to remain calm and move away slowly, rather than swatting or making sudden movements. Swatting at an individual wasp is a direct threat that will provoke a sting and may trigger the release of the alarm pheromone. If a sting occurs, retreat quickly from the area, as the chemical signal may draw more wasps to the location.
Unlike honeybees, paper wasps have a smooth stinger, allowing them to sting repeatedly without dying. If a nest is large, located in a high-traffic area, or if residents have known allergies, professional removal should be sought. Experts can safely remove the nest, often doing so at night when the wasps are less active and mostly contained within the structure.