A hornet nest that buzzed all summer is usually dead by winter, because nearly every hornet in it dies when the cold arrives. The colony doesn’t end there, though. A handful of young queens slip away before the die-off and spend the winter alone and dormant.1PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France
Workers and Males Die While Young Queens Survive
Each nest starts with a single mated queen who survived the previous winter.2PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France As summer ends, a successful nest stops raising only workers and begins raising many new young queens.3PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France These young queens mate before winter.4PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France
Everyone else stays in the nest until they die in late autumn. That includes the workers and the males.5PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France The old founding queen dies too, since hornet queens live only about a year. By early winter, the colony that built the nest is gone.
Fall hornets often look slow or drowsy around the nest. Activity tapers on cool days and stops after hard frosts, and you may find dead or dying hornets near doors and windows.
Late summer is also when hornets seem most aggressive. The colony is at its largest, and the workers no longer have young to feed, so they go looking for sugary food. That’s why fall picnics and trash cans attract them. The aggression ends when the workers die.
Inside, the nest is built in stacked layers of paper cells. Late in the season the lower layers may hold the last larvae being raised as queens. Once the old queen’s egg-laying slows, nothing replaces the workers who are dying, so the colony shrinks even while the nest still looks large.
Where Hornet Queens Hide for the Winter
Young queens don’t hibernate in the nest they were raised in.6PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France Each one disperses to find her own hiding spot.7PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France A queen will hibernate in almost any small, dark space.8PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France
In nature, that means crevices in tree bark, hollow logs and leaf litter.9Rockland Bee Removal. What Happens to Large Hornet Nests in Winter? Some dig into soil.10Plunkett’s Pest Control. Where Do Wasps Go in the Winter? Around homes, they can end up in attics, sheds or basements.11Plunkett’s Pest Control. Where Do Wasps Go in the Winter?
Tight, dark crevices work because a snug space protects a sleeping queen from rain, wind and sudden temperature swings that would drain her reserves. Enclosed spots also hide her from birds and other animals that hunt in the open. That’s why rotting logs, loose bark and woodpiles are favorites, and why gaps behind siding can appeal to her as well.
In autumn you may see a queen crawling slowly along walls, fence posts or tree trunks, searching. Once she finds a suitable spot, she tucks in her legs and antennae and stays still all winter.
That also means a lone hornet in an attic or garage in winter is likely a dormant queen. Heating can wake her too early, which is why she may turn up on a sunny winter day. She is sluggish and unlikely to sting unless handled, so use a jar and a card to remove her rather than bare hands.
A single hornet doesn’t mean a nest in the wall, and nests are not normally active in winter. If you want fewer hiding spots, seal gaps in eaves and vents in late summer.
How Queens Survive the Cold
Before winter, young queens enter a deep dormancy where growth and activity pause. It is a programmed shutdown that begins before harsh weather arrives, so the queen is already prepared when cold sets in. Short days and falling temperatures in autumn are the usual cues.
She needs fuel for the shutdown, and fat stores are highest around mating time.12PubMed. Changes in biogenic amine levels and physiological traits of the reproductive caste during caste-specific life events in temperate paper wasps Once dormant, she uses very little energy. In a related bee, dormant queens burn energy at less than 5% of their normal resting rate.13PubMed. Metabolic Rate Suppression and Maintenance of Flight Muscle Metabolic Capacity during Diapause in Bumble Bee (Bombus impatiens) Queens Oriental hornet queens from colder, longer-winter regions are larger, carry more fat and burn energy about 30% slower.14Ecological Entomology. Body size, metabolic rate and diapause in the oriental hornet (Vespa orientalis), in two extreme climatic regions
Even so, the budget is fixed. Dormant queens slowly lose weight, protein and fat over winter as they use up reserves,15Frontiers in Microbiology. Associations between gut microbiota dynamics and fat body metabolic remodeling in overwintering Vespa velutina queens and their sugar stores drop too.16Frontiers in Microbiology. Associations between gut microbiota dynamics and fat body metabolic remodeling in overwintering Vespa velutina queens A queen who goes in thin may not last until spring.
Freezing is the other threat. Many overwintering insects survive by keeping their body fluids from freezing even below 0°C. They remove particles that would seed ice crystals and build up antifreeze-like sugars and proteins.17PubMed Central. Physiology of cold tolerance in insects Shelter helps too. In Alaska, queens of yellowjackets, close hornet relatives, stayed near -6.5°C under leaf litter and snow while the air dropped to -40°C.18Physiological Zoology. Overwintering in Yellowjacket Queens (Vespula vulgaris) and Green Stinkbugs (Elasmostethus interstinctus) in Subarctic Alaska Raking away every leaf removes some natural shelter, though queens use many other spots.
What Happens to the Old Nest
Once the queens leave and the others die, the nest is empty and inactive.19PubMed Central. Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae): a case study of a commune in south-west France Hornets use a nest for only one season, even after building it for months.20Ecosphere. Gathering in an empty house: Arthropod assemblages overwintering in abandoned hornet nests Queens never rebuild an old nest; each starts a new one in a new place.21Buckeye Yard and Garden Line. Collecting Baldfaced Hornet Nests: BE CAREFUL
Waiting until winter or spring all but removes the sting risk.22Buckeye Yard and Garden Line. Collecting Baldfaced Hornet Nests: BE CAREFUL Winter weather often tears nests apart, so pristine ones are rare by spring.23Buckeye Yard and Garden Line. Collecting Baldfaced Hornet Nests: BE CAREFUL Empty nests can also shelter other overwintering insects and spiders.24Ecosphere. Gathering in an empty house: Arthropod assemblages overwintering in abandoned hornet nests
Taking it down is mostly about appearance or peace of mind, especially if it hangs near a door or play area. Leaving it up is fine too, since it won’t be reused.
If you do take it down, wait until after several hard frosts with no hornet traffic. Watch the entrance for a few minutes on a mild day first. Wear gloves and bag the nest whole.
You may want to keep it. Hornet nests are made of chewed wood fiber mixed with saliva, so they are light and papery and keep well when dry indoors. Cut it down only after the colony is clearly gone, and handle it gently because it is fragile. Check for spiders and other insects tucked inside before bringing it in.
How Hornets Return in Spring
Queens wake when spring temperatures stay warm enough for long enough. In one related wasp, emergence needed temperatures above about 17–18°C and a build-up of warm days.25Ecologies. Thermal Requirement for Spring Emergence of Potter Wasp Parancistrocerus fulvipes: Implications for Population Management Under Climate Change
Dates still vary. Queens in warmer regions or sunny, sheltered yards tend to wake earlier than those in cold, shaded spots. A queen buried in soil may warm more slowly than one under south-facing bark, so queens in the same area don’t all emerge on the same day.
Each queen emerges alone and begins a new nest.26The Conversation. ‘Spring queening’ time will be crucial for finding any surviving yellow-legged hornets She must gather food, build and raise the first young herself,27The Conversation. ‘Spring queening’ time will be crucial for finding any surviving yellow-legged hornets so early spring is when colonies are smallest and most fragile.
First she needs to feed, often on sugary sources like sap or early flower nectar, to regain energy after months of fasting. Then she scouts for a nest site, which may be a sheltered tree hollow, a roof overhang, a shrub or a shed. She chews wood fiber into paper and builds the first small cells herself before laying eggs.
The nest starts golf-ball sized with a few paper cells, and only one hornet, the queen, comes and goes. Removing it at this stage is much easier and safer than in summer. It grows quickly once the first workers hatch a few weeks later. After that the queen mostly stays inside laying eggs while the workers take over foraging and building. The hornets you see flying are workers.
In April and May, look under eaves, in sheds and on shrubs. A single large hornet flying low around structures may be a queen scouting. For nests in walls or high spots, call a professional.
What Kills Queens Before Spring
Many queens die over winter, but freezing deaths among sheltered queens appear rare.28Physiological Zoology. Overwintering in Yellowjacket Queens (Vespula vulgaris) and Green Stinkbugs (Elasmostethus interstinctus) in Subarctic Alaska Other causes matter more. Running out of stored fat is one, since reserves fall all winter.29Frontiers in Microbiology. Associations between gut microbiota dynamics and fat body metabolic remodeling in overwintering Vespa velutina queens Fungal diseases can infect wasps too, though in one paper wasp population only about 3% of nests showed infection.30PubMed Central. Identity, Prevalence, and Pathogenicity of Entomopathogenic Fungi Infecting Invasive Polistes (Vespidae: Polistinae) Paper Wasps in New Zealand
Predators take some. Birds, spiders and rodents find certain hidden queens. Many spring nests also fail before the workers hatch. A single nest can produce many young queens, but only a small share survive winter and found successful nests.
Hornet species differ in how they prepare for winter. Invasive Asian hornet queens carry less fat than European hornet queens and develop eggs about a month earlier.31PubMed Central. Comparison of reproductive traits of foundresses in a native and an invasive hornet in Europe
Some areas trap spring queens to fight invasive Asian hornets, since each queen caught can mean one less nest. Traps also catch harmless insects, so follow local guidance.