Winter: mated queens hibernate 6–9 months. Spring: queens emerge (March–May UK) and found nests. Summer: workers, then males and new queens. Autumn: colony dies; new queens hibernate. Peak size: 30–400+ bees (University of Wisconsin; BBCT).
Bumble bee life cycle
The bumble bee life cycle runs on a one-year clock. A single queen who survived the winter starts a colony in spring, raises workers through the summer, then switches to raising males and new queens; in autumn the colony dies, and only the new queens survive, hibernating until the next spring (Bumblebee Conservation Trust; University of Wisconsin). Unlike a honey bee hive, a bumble bee colony never lasts more than one season: "the colonies are annual, with queens emerging in spring, and producing new queens that same fall which will found new colonies of the following year" (University of Wisconsin).
Choose a month and your hemisphere above to see where a colony is in that cycle, what you're likely to notice in the garden, and simple ways to help. The calendar is the same one used by the bumble bee lifespan calculator, so the two pages always agree on the season.
Bumble bee colony cycle in brief
- Hibernation (winter): mated queens rest alone, usually in soil, for 6–9 months (University of Wisconsin).
- Emergence (early spring): queens wake, feed on flowers and search for a nest site.
- Nest founding: each queen builds a small wax nest, lays her first eggs and raises the first workers alone.
- Colony growth (late spring–summer): workers take over foraging; the queen stays home laying eggs.
- Males and new queens (summer–early autumn): the colony switches to raising the next generation of reproductives.
- Decline (autumn): the old queen, workers and males die; new queens mate and go into hibernation.
That bumble bee colony cycle is the same for most temperate species; what changes from one species to the next is the timing and how big the colony gets.
From hibernating queen to new colony
Everything starts with one queen. In autumn she fed heavily — new queens are fed "up to three times more pollen" as larvae and then feast on the nest's stores, because "the more energy they can store as body fat now, the better their chances of surviving winter hibernation" (Bumblebee Conservation Trust). Over winter she lives on that fat, protected by natural antifreeze-like compounds in her body (University of Wisconsin).
When do bumble bee queens come out?
When do bumble bee queens come out of hibernation? In the UK, "roughly March–May depending on species and weather conditions" (Bumblebee Conservation Trust); in Wisconsin, "typically in mid to late April and early May" (University of Wisconsin). Different species wake at different times, so the first big queens of spring may be a month ahead of others. A queen that has just woken often rests on the ground "with very little flying or feeding" at first, which is normal (Bumblebee Conservation Trust).
Finding a nest site
Once she has fed, the queen goes house-hunting. She "will fly in a slow and distinctive zig zag pattern, often low over the ground or around features that might be suitable", landing to crawl into likely holes and sometimes disappearing for a few minutes before coming out to keep searching (Bumblebee Conservation Trust). Popular choices include "long tangled grass, compost heaps, bird boxes, and abandoned mouse and vole holes" (Bumblebee Conservation Trust) — bumble bees are "cavity" nesters (University of Wisconsin). A queen seen carrying pollen on her hind legs has found her home (Penn State Extension).
The first brood
In her chosen chamber the queen makes wax from her body, shapes a small pot and fills it with nectar, packs a lump of pollen and lays her first eggs on it, then sits on the brood to keep it warm by shivering her flight muscles (Bumblebee Conservation Trust). The eggs hatch after 4–6 days, the larvae feed for 2–3 weeks before spinning cocoons, and adults emerge about two weeks later (Bumblebee Conservation Trust). The first workers appear two to three weeks after the eggs are laid according to the University of Wisconsin, or after about three to four weeks of development according to Penn State Extension. Until they do, the queen has to keep the brood warm and fetch food alone — the riskiest weeks of the cycle.
Bumble bee nest life cycle
The bumble bee nest life cycle looks quite different from a honey bee hive. Inside there is no neat honeycomb: the nest "can appear quite messy and disorganised", with little wax pots for nectar, wax brood cells and the silk cocoons of bees developing into adults (Bumblebee Conservation Trust). The nest holds a steady temperature of about 30 °C even on cold days (University of Wisconsin). When it's finished, the queen's body and some dead workers are left inside, and the nest "will just gradually degrade and break down" (Bumblebee Conservation Trust).
Bumble bee colony stages by month
The table shows the colony stage for each month in both hemispheres. The Northern Hemisphere column is based on UK and Wisconsin timings; the Southern column is the same pattern shifted by six months (our assumption).
| Month | Northern Hemisphere | Colony size (North) | Southern Hemisphere |
|---|---|---|---|
| January | Queens hibernating | No colony — only lone queens | Males and new queens |
| February | Queens hibernating | No colony — only lone queens | Males and new queens |
| March | Queens waking | No colony yet — the queen is alone | Males and new queens |
| April | Queens waking | No colony yet — the queen is alone | Colony ending |
| May | Queens founding nests | The queen and her first few workers | Queens hibernating |
| June | Colony growing | Growing towards a peak of about 30 to 400 or more bees, depending on species | Queens hibernating |
| July | Males and new queens | At or past its peak — up to about 400 bees | Queens hibernating |
| August | Males and new queens | At or past its peak — up to about 400 bees | Queens hibernating |
| September | Males and new queens | At or past its peak — up to about 400 bees | Queens waking |
| October | Colony ending | Dwindling; only new queens will survive | Queens waking |
| November | Queens hibernating | No colony — only lone queens | Queens founding nests |
| December | Queens hibernating | No colony — only lone queens | Colony growing |
Sources: Bumblebee Conservation Trust; University of Wisconsin; Penn State Extension. Colonies switch to raising males and new queens anywhere from late June to August–September depending on species (University of Wisconsin), so the "males and new queens" months stretch across late summer.
How big do bumble bee colonies get?
How big do bumble bee colonies get? Small, by honey bee standards: from about 30 to upwards of 400 individuals at the peak (University of Wisconsin). The Bumblebee Conservation Trust says a well-established nest "can contain up to 400 bumblebees and could be around the size of a small football", while "some species have much smaller nests with only around 50 workers at their most active". A honey bee hive, for comparison, can hold 50,000 bees.
Workers, then males and new queens
Workers live about four to six weeks (Bumblebee Conservation Trust), so the queen keeps laying to replace them. The bigger, stronger workers do most of the foraging, while smaller ones tend to stay in the nest to keep it warm, defend it and clear out dead brood (Bumblebee Conservation Trust). Later in the season some workers start laying unfertilized eggs of their own, which become males — the "competition phase" (Penn State Extension). The final brood produces the males and new queens that carry the species into the next year.
What happens in autumn
Autumn is the end of the colony and the beginning of the next one. "As summer fades to autumn, the old queen and all the workers and males die off, while the new queens enter hibernation" (Bumblebee Conservation Trust). The founding queen dies naturally with the last of her workers (Penn State Extension). Males leave the nest to find new queens from other colonies and never return; they "spend their days hanging out on flowers, drinking nectar, and flying around looking for queens" until they die a few weeks later (Bumblebee Conservation Trust).
Old workers near the end of their lives often cling to flowers and look lethargic, and several may be found dead under the same bee-friendly plants (Bumblebee Conservation Trust) — a normal sight in late summer, not a sign that something has gone wrong.
Bumble bee hibernation
Bumble bee hibernation is done by the new queens alone. After mating they dig into loose soil, banks of earth and thatch — often north-facing soil (Bumblebee Conservation Trust) — and stay there for 6–9 months (University of Wisconsin). If you dig one up by accident, cover her loosely with the same material so she can dig out later; if she won't settle, put her somewhere sheltered such as under leaf litter rather than taking her indoors (Bumblebee Conservation Trust).
Winter-active bumble bees
In parts of Britain, buff-tailed bumblebee queens have started nests in autumn instead of hibernating, and these winter colonies feed on winter-flowering shrubs (Bumblebee Conservation Trust). The calendar above describes the usual one-year cycle; a bumble bee flying in mid-winter in a mild area may belong to one of these winter nests.
How to help bumble bees through the year
The Xerces Society sums up what bumble bees need: flowers to forage on, a place to nest and a pesticide-free environment. Here is how that translates into the colony calendar:
- Late winter and early spring: early blossom feeds queens straight out of hibernation, before they can start a nest (Bumblebee Conservation Trust).
- Spring nest-hunting: leave some rough grass, compost heaps and undisturbed corners for queens to nest in, and hold off mowing tangled grass where you see a queen going in and out (Bumblebee Conservation Trust).
- Summer: a continuous run of flowers keeps colonies growing — a colony can fail "before they can produce queens, as there are not enough flowers to feed on" (Bumblebee Conservation Trust).
- Late summer and autumn: late flowers feed the new queens building up fat for winter.
- All year: avoid pesticides (Xerces Society), and leave a nest in place if you find one — it lasts only a few months and causes no damage (Bumblebee Conservation Trust).
- A grounded bee: it's probably resting; queens rest for about 30 and up to 45 minutes. Only as a last resort, offer a drop or two of 50/50 white sugar and water — never honey or brown sugar (Bumblebee Conservation Trust).
How this calendar works
- Stage: the month is matched to the bumble bee year: queens hibernating (December–February in the North), queens waking (March–April), nest founding (May), colony growing (June), males and new queens (July–September) and colony ending (October), then hibernation again. This is the same calendar used by the bumble bee lifespan page.
- What you'll see and how to help: written for each stage from the Bumblebee Conservation Trust, the University of Wisconsin, Penn State Extension and the Xerces Society.
- Region: the Northern months combine UK and US (Wisconsin) sources; species, altitude and weather shift them by weeks. The Southern Hemisphere is shifted by six months — an assumption, as the sources are northern.
For how long each bumble bee lives — queens, workers and males — see the bumble bee lifespan calculator; for how long a nest lasts compared with a hive or a wasp nest, see the hive and nest lifespan page.
Frequently asked questions
What is the bumble bee life cycle?
A one-year cycle: a queen wakes from hibernation in spring, founds a nest, raises workers, then males and new queens; the colony dies in autumn and only new queens hibernate (Bumblebee Conservation Trust; University of Wisconsin).
When do bumble bee queens come out?
Roughly March to May in the UK (Bumblebee Conservation Trust) and mid-April to early May in Wisconsin (University of Wisconsin), depending on species and weather.
Does a bumble bee colony survive more than one year?
No. Colonies are annual: only the new mated queens survive the winter, and each starts a new colony in spring (University of Wisconsin; Bumblebee Conservation Trust).
How big do bumble bee colonies get?
About 30 to upwards of 400 bees at the peak (University of Wisconsin); some species only about 50 workers (Bumblebee Conservation Trust).
Where do bumble bees nest?
In cavities: long tangled grass, compost heaps, bird boxes and old mouse and vole holes (Bumblebee Conservation Trust).
Where do bumble bee queens spend the winter?
Alone, dug into loose soil, banks or thatch — often north-facing soil — for 6–9 months (Bumblebee Conservation Trust; University of Wisconsin).
What happens to bumble bees in autumn?
The old queen, workers and males die off, and the new mated queens go into hibernation (Bumblebee Conservation Trust).
How long from egg to adult bumble bee?
Eggs hatch after 4–6 days, larvae feed 2–3 weeks and pupae take about two more (Bumblebee Conservation Trust).
Do bumble bees reuse their nest?
No — a queen always starts from scratch, though another queen may use the same spot the next year (Bumblebee Conservation Trust).
Why do I see big bumble bees flying low in spring?
They are queens searching for nest sites in a slow zig-zag over the ground (Bumblebee Conservation Trust).
How can I help bumble bees?
Flowers from early spring to autumn, undisturbed nest and hibernation spots, and no pesticides (Xerces Society; Bumblebee Conservation Trust).
For education. Bees are pollinators — never spray a swarm or a colony. For a swarm or bees in a wall, contact a local beekeeper, a certified bee-removal specialist or your Extension office (UGA Extension; Mississippi State). Follow your local apiculture or Extension guidance on varroa and colony care. If a sting causes trouble breathing, swelling of the face or throat or faintness, call emergency services.