Hornets are social wasps, living in colonies with a queen, workers, and males. Like other insects, hornets hibernate to endure harsh environmental conditions. Only newly mated queen hornets undergo this dormancy, while the rest of the colony perishes with colder weather. This allows the queen to survive the winter and establish a new colony in the following spring.
The Timing of Hornet Hibernation
Hornet hibernation begins in late autumn or early winter. The primary triggers are dropping ambient temperatures and decreased food sources. As the days shorten and temperatures decline, the hornet colony’s activity diminishes, signaling the approaching end of their active season.
The decline in food prompts new queens to seek shelter. Without sufficient sustenance, workers and males die off, leaving only fertilized queens to overwinter. This dormancy, also known as diapause, is crucial for the queen’s survival until spring.
Where Hornets Hibernate
Queen hornets seek protected and secluded locations to hibernate, ensuring safety from cold temperatures, predators, and environmental disturbances. Common natural hiding spots include crevices in tree bark, rotting logs, and burrows or holes in the soil. These sites offer insulation and stability, helping the queen maintain a consistent, low body temperature.
Man-made structures also provide suitable hibernation sites. Attics, wall voids, sheds, and window frames offer sheltered spaces where they can remain undisturbed throughout winter. The selection of these locations is driven by the need for protection and a stable environment, as a location that is too warm might cause premature awakening.
The Hibernation Process
During hibernation, the queen undergoes significant physiological changes to conserve energy. This state is more accurately described as diapause, a form of dormancy, rather than true sleep. The queen’s metabolic rate drops considerably, and her body temperature lowers to match the surrounding environment.
This metabolic suppression allows her to survive without food or water. Some queen wasps, including hornets, can produce a natural antifreeze substance, which helps prevent ice crystals from forming within their bodies, enabling them to endure cold temperatures without freezing. This adaptation is essential for surviving winter and ensuring the continuation of the species.
Post-Hibernation: Colony Re-establishment
As spring approaches and temperatures begin to rise (typically March to May), the hibernating queen emerges from her dormant state. Her initial activity involves searching for nectar to replenish energy reserves, as adult wasps consume liquid foods. The queen then seeks a suitable location to build a new nest for her future colony.
Once a location is chosen, she begins constructing the initial nest structure using chewed wood pulp and saliva. She then lays her first batch of eggs, which will hatch into larvae and eventually develop into worker hornets. These workers will then take over nest construction and foraging duties, allowing the queen to focus on laying eggs and expanding the new colony.