Most social wasps in temperate regions enter dormancy in autumn, roughly when nighttime temperatures consistently drop below about 10°C and daylight hours shorten past a critical threshold. Only the newly mated queens survive to hibernate; workers, males, and the old queen all die as the colony collapses. Those queens tuck themselves into sheltered crevices and enter a state called diapause, a deep physiological shutdown far more dramatic than simple sleep. Where they hide, how their bodies manage months without food, and what determines whether they wake up at all are questions with genuinely interesting answers that go well beyond the simple “they hibernate in winter” summary.
What Triggers Dormancy
Wasp dormancy is not switched on by a single event. It results from the interplay of two environmental signals: shrinking day length (photoperiod) and falling temperature. Research on parasitoid wasps has shown that the diapause response is primarily driven by photoperiod and then fine-tuned by temperature, fitting the classic definition of facultative diapause commonly seen in species that produce multiple generations per year.1Annals of the Entomological Society of America. Role of Photoperiod and Temperature in Diapause Induction of Endoparasitoid Wasp Microplitis mediator (Hymenoptera: Braconidae) The same general pattern holds for social wasps. As summer wanes, the shortening days act as a calendar that tells the colony’s physiology to shift gears, and dropping temperatures reinforce the message.
What makes this especially interesting is that the mother, not the offspring, often controls the switch. In at least one well-studied wasp species, researchers found that a hormone called juvenile hormone plays a decisive role. When day length gets short, levels of juvenile hormone in the mother’s blood drop, and she begins producing offspring destined for diapause. Experimentally knocking down the gene responsible for making juvenile hormone caused mothers to produce diapause-ready offspring even under long summer-like days, while applying the hormone directly reversed the effect and suppressed diapause production under short days.2ResearchGate. Juvenile hormone as a causal factor for maternal regulation of diapause in a wasp In other words, queens born in late summer are chemically programmed for dormancy before they even emerge from the nest, based on the hormonal state of the queen that produced them.
Where Queens Go to Overwinter
After mating in late summer or early autumn, young queens leave the dying colony and search for a protected spot to spend the winter. These hiding places, called hibernacula, need to satisfy a few basic requirements: they should be cool enough to keep the queen’s metabolism low, insulated enough to prevent lethal freezing, and dry enough to avoid fungal infection or desiccation. Common choices include gaps beneath loose bark, crevices in stone walls, soil cavities, hollow plant stems, unheated sheds, and attic spaces. Queens are not picky about the specific material so much as the microclimate it creates.
Many paper wasp species take this a step further by clustering together in groups, sometimes dozens of queens packed into a single sheltered spot. This aggregation behavior is more than coincidence. Huddling together buffers temperature swings and helps maintain a more stable humidity, which in turn reduces the energy each queen burns to stay alive and lowers the stress of water loss over the winter months.3PubMed Central. Does the Aggregation Behavior of Overwintering Paper Wasp Gynes Provide Energetic Benefits? A queen overwintering alone in an exposed crack is more vulnerable to both cold snaps and dry spells than one buried in a cluster of her sisters. If you have ever peeled back a piece of siding in early spring and found a knot of seemingly lifeless wasps, you were looking at one of these aggregations.
Yellowjackets and hornets tend to be more solitary hibernators than paper wasps, though they seek out similar environments. European hornet queens, for example, favor soil cavities and rotting logs, while common yellowjacket queens often burrow a few centimeters into loose soil or leaf litter. The key for all of them is avoiding prolonged exposure to temperatures below roughly minus five to minus ten degrees Celsius and staying out of direct contact with standing water.
How Queens Survive Months Without Eating
A hibernating wasp queen eats nothing from autumn until spring. She survives entirely on fat stored in her body before entering diapause. Measurements of overwintering oriental hornet queens found a respiratory quotient of 0.71, which confirms that lipids are the exclusive fuel burned during dormancy, with no protein or carbohydrate being used at all.4Ecological Entomology. Body size, metabolic rate and diapause in the oriental hornet (Vespa orientalis), in two extreme climatic regions This matters because fat is the most energy-dense fuel available, giving the queen the longest possible runway on a finite tank.
Body size turns out to be a meaningful predictor of survival. Larger queens tend to carry proportionally more fat than smaller ones, which means they can sustain diapause for longer stretches.4Ecological Entomology. Body size, metabolic rate and diapause in the oriental hornet (Vespa orientalis), in two extreme climatic regions A queen that enters winter underweight, perhaps because the colony she came from was struggling or because autumn forage was poor, has a worse chance of making it to spring. This is one reason why late-season colonies that are still active and producing queens in October sometimes produce queens that are less likely to survive: they may simply run out of time to fatten up before cold forces them into hiding.
During diapause, the queen’s metabolic rate drops to a fraction of its active-season level. Her muscles are inactive, her digestive system shuts down, and she enters a state of near-total stillness. Internally, special antifreeze-like compounds, primarily glycerol and other cryoprotectants, accumulate in her body fluids to prevent ice crystals from forming in her cells. These biochemical defenses are assembled before diapause begins and are gradually broken down once temperatures rise in spring.
Social Wasps Versus Solitary Wasps
The “queen hibernates while the colony dies” story applies specifically to social wasps, the yellowjackets, hornets, and paper wasps that live in colonies. But the majority of wasp species on Earth are actually solitary, and their dormancy strategy looks quite different.
Many solitary wasps overwinter not as adults but as immature stages, often prepupae sitting inside sealed nest cells. The grass-carrying wasp, for example, spends the winter as a prepupa inside a cocoon, then pupates and emerges as an adult only after temperatures climb above a developmental threshold of roughly 14°C.5Journal of Thermal Biology. Effect of temperature on the post-diapause developmental rate, survival, and body mass of the solitary wasp Isodontia elegans The adult never experiences winter at all. It hatches in spring or early summer, mates, provisions a nest, and dies before autumn, leaving its offspring sealed in cocoons to ride out the cold months. Mud daubers, mason wasps, and many parasitoid wasps follow similar patterns.
This means the answer to “where do wasps go in winter” depends entirely on which wasp you are asking about. For social species, the answer is sheltered adult queens in hibernacula. For many solitary species, the answer is immobile prepupae or pupae sealed inside nest cells in hollow stems, holes in wood, or mud chambers attached to walls and eaves. Both strategies are forms of diapause, but the life stage and the physical location are completely different.
When Dormancy Does Not Happen
Not all wasp populations follow the neat annual cycle of colony birth, growth, decline, and queen hibernation. In mild climates where winter temperatures stay above freezing, some colonies simply keep going. Research on the western yellowjacket in Hawaii found that colonies on both Maui and Hawaii Island sometimes overwintered as active colonies rather than shutting down, and that autumn queens were more often ready to lay eggs immediately than to enter hibernation, suggesting that winter dormancy is not a fixed obligation for these populations.6New Zealand Journal of Zoology. Reproductive plasticity of Vespula pensylvanica (Hymenoptera: Vespidae) on Maui and Hawaii Islands, U.S.A.
These perennial colonies can grow enormous. Without the annual reset of winter dieback, a colony that would normally max out at a few thousand workers in a temperate summer can persist for years and expand to tens of thousands of individuals. This has serious ecological consequences in places where yellowjackets are invasive, like Hawaii and New Zealand, because the year-round colonies consume vastly more prey, including native insects, than their seasonal counterparts do elsewhere.
Even in temperate regions, unusually mild winters occasionally allow a colony to survive into the next year. These overwintered colonies get a massive head start over newly founded spring nests and can become much larger than normal by midsummer. Pest control professionals in parts of the southern United States and southern Europe sometimes encounter these “super nests,” which can fill an entire wall cavity or attic space. They are not a separate species; they are ordinary yellowjacket or hornet colonies that lucked into a winter warm enough to keep the queen and a core of workers alive.
What Dormant Queens Carry With Them
A hibernating queen is not just preserving herself. She is also preserving the microbial passengers she picked up during her active life. Research on European hornets and paper wasps demonstrated that queens overwintering as adults can harbor yeast cells in their gut from autumn all the way through to spring, then pass those yeasts on to their offspring when they found new colonies.7PubMed Central. Role of social wasps in Saccharomyces cerevisiae ecology and evolution The yeast in question is the same species used in bread-making and winemaking. The wasps essentially serve as a winter refuge for the yeast, bridging the cold months when ripe fruit is unavailable, and then reintroduce it to the environment in spring when they visit flowers and fermenting fruit.
This finding reframed how ecologists think about the relationship between wasps and the microbes they carry. A hibernating queen is not a blank slate waiting to start fresh; she is a biological vault, carrying a community of gut microorganisms through a season that would otherwise wipe them out. It is one of the more surprising examples of how an insect’s dormancy matters not just for the insect itself but for entirely different organisms that depend on it as a host.
Climate Change and the Cost of Warming Winters
You might assume that warmer winters would be good news for hibernating wasp queens, since they would face less risk of freezing. The reality is more complicated and, for the wasps, largely bad. A queen in diapause burns through her fat reserves at a rate determined by her metabolic rate, and metabolic rate rises with temperature even during dormancy. A winter that is a few degrees warmer than normal does not wake the queen up early; it just forces her body to burn fuel faster while she remains inactive.
Simulations based on measured metabolic rates of overwintering paper wasps found that a 1°C rise in ambient winter temperature increased the total energy a queen burned during dormancy by roughly 14 to 18 percent, depending on species and location. A 2°C rise pushed costs up by about 27 to 33 percent, and a 3°C rise by 36 to 45 percent.8PubMed Central. The Impact of Climate on the Energetics of Overwintering Paper Wasp Gynes (Polistes dominula and Polistes gallicus) Those are steep increases. A queen that would comfortably survive a normal winter on her fat reserves could starve before spring arrives if the winter is consistently a couple of degrees warmer than her physiology expects.
The paradox is worth sitting with: warming does not necessarily help overwintering insects. For species locked into obligate diapause, where the queen cannot simply wake up and forage when it is warm in January, higher temperatures during dormancy are a pure drain with no compensating benefit. The queen cannot eat, cannot reduce her metabolic rate voluntarily, and cannot emerge early enough to find food. She just burns through her reserves faster. This may partly explain why some wasp populations in warming regions are shifting their phenology, emerging earlier in spring or entering diapause later in autumn, in ways that do not always align well with the availability of prey and nectar.
Finding Dormant Wasps in Your Home
If you live in a temperate area, there is a decent chance that a few wasp queens are spending the winter somewhere in or on your house. Attics, wall voids, gaps behind shutters, spaces under roof tiles, and the insides of rolled-up garden umbrellas are all popular hibernation spots. The queens are completely inactive and pose essentially zero sting risk during this period. They are not guarding a nest, they have no colony to defend, and their muscles are too cold and sluggish to mount a response even if you picked one up (though you should not test that theory in a heated room).
Problems arise in two scenarios. First, if your attic or wall void is heated enough to keep interior temperatures well above freezing, queens may wake up prematurely on warm days in late winter and end up buzzing around windows inside your house, disoriented and unable to find food. This is annoying but not dangerous in any meaningful way; the wasps are groggy and weak, and the simplest solution is to gently trap them in a glass and release them outside, where they will find another sheltered spot to resume dormancy if it is still cold. Second, if you seal up entry points while queens are inside, they may emerge in spring with no way out and end up dying in your walls, or worse, founding a new colony in your attic before you realize they are there.
The practical advice is straightforward. Seal gaps and cracks in autumn before queens have moved in, or wait until late spring when any queens that overwintered inside have already left. If you find a cluster of dormant queens in winter, you can leave them alone if they are in a spot that does not bother you; they will leave on their own in spring. If they are somewhere problematic, you can carefully relocate them to an unheated shed or sheltered outdoor spot. Killing dormant queens is legal and sometimes necessary, but each queen you remove in winter is one fewer colony founded in your yard come spring, so the decision is partly about how many wasps you are comfortable living near in the summer months that follow.
Spring Emergence and What Comes Next
Queens typically emerge from diapause in mid to late spring, triggered by sustained warmth rather than a single warm day. The exact timing varies by species and latitude; paper wasp queens in the Mediterranean may be active by March, while yellowjacket queens in northern Europe or the northern United States often do not appear until May. After waking, a queen spends her first days feeding heavily on nectar and sap to replenish the energy reserves she burned through over winter. She is conspicuously slow and clumsy during this recovery period, and you may notice large wasps visiting early spring flowers or hovering around sap-bleeding trees in a sluggish, unfocused way.
Once she has regained enough energy, the queen begins searching for a nest site. Paper wasps build exposed combs under eaves and overhangs. Yellowjackets prefer underground cavities or enclosed voids. Hornets look for sheltered spots high in trees or in attic spaces. The queen constructs the first few cells herself, lays eggs, and raises the initial brood of workers entirely on her own. Only after those first workers emerge does the colony begin to grow rapidly, with the queen shifting to a full-time egg-laying role while workers take over foraging, construction, and defense. The entire cycle, from solitary queen in spring to a colony of hundreds or thousands by late summer, plays out in a matter of months before the next generation of queens mates, disperses, and vanishes into hibernation once again.