wild bees and native bees

Where do bumble bees go in winter?

A black and white early spring bumble bee on pink claytonia, a woodland plant. Rusty Burlew

Unlike honey bee colonies, bumble bee colonies do not overwinter. Instead, only newly mated queens survive by hibernating in a protected spot.

Do bumble bees fly south? Hibernate? Keep themselves warm like honey bees? Why don’t we see them flying around on a warm winter day?

Even though honey bees and bumble bees are closely related (in the family Apidae) and even though they are both social bees, their life cycles are very different. While entire honey bee colonies can survive a northern winter, bumble bee colonies cannot.

A newly mated queen hibernates in the ground

A newly mated bumble bee queen overwinters by hibernating in a small nest in the ground, just big enough for her. This tiny abode, known as a hibernaculum exists 5 to 15 cm below the soil surface. For safety, the tiny opening is often obscured by mulch or leaf litter. As winter temperatures get colder, the queen produces a chemical in her body (glycerol) that keeps her from freezing, and she remains buried all winter.

After she emerges in the spring, the queen searches for a site to use as a nest for her future colony. Spring queens examine holes in the ground, looking for potential nesting sites. They often prefer sites that once belonged to other animals such as rodents or birds. The queen may go in and out of a potential site many times before moving on or making a selection.

Some species of bumble bees search for a nest above ground. Popular spots include empty bird nests, mailboxes, compost heaps, and barn lofts.

Starting a family in spring

Once she has decided on a site, the queen begins building a nest, laying eggs, and foraging for nectar and pollen. At first, she does all the work by herself–a single working mother. But after the first batch of brood emerges, the new workers assist in foraging, nest maintenance, and raising their sisters. Eventually, the queen will have produced enough workers that she no longer has to leave the nest, and egg-laying becomes her full-time job.

The population of the bumble bee nest continues to increase all summer and into the fall. But at some point, often late in summer, the queen begins to produce virgin queens and males instead of just workers. These new queens and male bees mate with bees from other colonies.

The cycle repeats in autumn

After mating, a new queen goes off to find a place to spend the winter just as her mother did. The rest of the colony, including all the workers, the males, and the original queen, perish with the approach of winter. Each of the hibernating queens, by herself, will awake in spring and begin the daunting task of finding a home and building a brand new colony from scratch.

Rusty
Honey Bee Suite

Bumble-bee-on-herb-robert
A summer bumble bee forages on herb-robert. Photo © Rusty Burlew.

66 Comments

  • Thank you for the neat summation of a bumble bee’s life cycle. Last summer I started _really_ noticing bumble bees and I have a feeling I’m going to be at/for them even more as time goes on. To me they’re inexplicably charming and I love to see them in the garden or looping around me as they visit the flowers around the patio.

  • There is just so much in this world that is so remarkable, I never get tired of studying how nature “gets it done.” Thank you again Rusty for sharing!!

  • I’ve a question for you. I live in an old Victorian home. This morning I was sitting at my desk working when I heard this constant drone. I figured it was someone doing lawn work nearby. Then I looked up to see a huge bumble bee trapped between the glass and the screen at a window. After a good twenty minutes of strategizing, I finally managed to capture it and set it free via a kitchen window. (No small feat, as I’m pretty uncomfortable with bees, wasps and hornets.) So my question is: Where did it come from? It can’t have gotten in via the window; it’s sealed up tight. Is it a safe guess that it was in here somewhere all this time, through the winter? I should add that this is the second one that’s been in my apartment over the past week, as spring has sprung. Any input would be greatly appreciated.

    • Schmadrian,

      I know this isn’t very helpful, but we have modern vinyl-framed double-paned windows. Every spring, dozens of mason bees get in the house. When I go outside, I can see them go in the drain holes that are part of the window frame (I grew up in an old Victorian home, so I know they don’t have such things). Anyway, from the inside it seems absolutely impossible that they could get in the house from the drain hole because it is sealed. We’ve held up burning matches looking for airflow, but nothing. We’ve nearly torn the windows apart looking for the connection, but we can’t find it.

      My point is that the bees probably came in from the outside, but you’re never going to know how! They may have come down the chimney or through a door, too. With only two, I wouldn’t worry too much. I’m glad you put it outside instead of killing it. Bees away from their nests aren’t aggressive towards humans. As long as you don’t accidentally grab it, you shouldn’t get stung.

      • Thanks, Rusty.

        Yesterday I realized a possible answer: this being an old Victorian home, there are crawl-spaces at four different places within the apartment. Cubby-holes, if you will. They’re locked, but there’s a space at the bottom of each door. A mouse darting across my kitchen floor from one to another reminded me of them. Perhaps this is how both bumblebees arrived.

        BTW: these would have been queens, yes?

        • Schmadrain,

          Most likely they are queens. Only the queens overwinter, and they may have spent that time in the crawlspace.

  • Hello, we have recently decided to do some renovations to our porch area. Have had a bumble bee hive in the wall 3 years in a row, found this out when removing the side wood panels and saw the old hives. Decided to do some research and made them a home for themselves. We moved the hive very carefully that was located within the insulation and placed it in the box. I sure love having the bumble bees around since they are located near my flower bed. They are so interesting to watch, my whole family loves to watch them. We sit near their hive daily and watch them. They never have been aggressive. Usually just buzz by back to the hive. They took to the box well after moving. It seems they improved with the move, the hive has transformed and has grown. I was just wondering how do I entice the new queen to come back to the box? Do I leave it out through the winter? Do I replace the bedding with new or leave the old hive there? I live in North Dakota so it is quite a few months of winter. I would love to attach some photos but have not figured out how to yet.

    • Heather,

      That sounds like so much fun. I would just leave the nest box alone and leave the bedding in place. There is a good chance that one of the new queens will choose to live in it next spring.

  • Thank you so much for the lesson on bumble bees. I live in Missouri, it is just starting to feel like fall around here. Some leaves are changing, but it will probably be another 2 weeks or so before things really start to get colorful. My husband and I have been working out in the yard today and I noticed on one little hill side there are probably 20 bumblebees flying around. They are flying just above the ground. They will land and crawl deep into the grass, they crawl back out, fly around some more….. Is it possible that we have 20 queen bees trying to hibernate in the same place, and if so does that mean we will have 20 nests near our home in the spring?

    • Kristina,

      It’s hard to say. Usually numbers of low-flying bees in the fall are males looking for females. However, if you think they are females searching for overwintering spots, you could be right. I don’t know what the numbers are, but I suspect only a very small percentage of mated queens actually make it until spring. Some get eaten, some starve, some freeze, some die of diseases or parasites, and some are lucky enough to make it. So even if you are correct and they are mated queens, I don’t think you will be overrun by bumbles in the spring.

  • Hi, I live in New Zealand and it is now in the winter season. Not overly cold here in Christchurch but we sometimes get snow. Yesterday I noticed a bumble bee lying on my path near the house. I thought it was dead and went to move it but it stretched its wee legs and I could see its body was moving. I gently manoevered it onto a pot with some flowers so it was sheltered overnight. This morning it was still in the same place so carefully moved it into a very warm sunny place and made up a small mix of honey and water which I placed in front of it and really enjoyed watching Mr/Mrs Bumble gobble it up. Question is will this bee survive or is it actually in the process of dying? Is there anything else I can do? They are really beautiful creatures.

    • Hi Carol,

      I don’t know much about your climate, but the bees survival probably depends on how much warm weather you have and how many flowers are in bloom. It is probably a queen, because only the queens overwinter in colder climates. She may have simply emerged too early or was dug up accidentally, perhaps by an animal. My guess is that she probably won’t make it.

  • We are building a front porch. With removing the cement in the front we uncovered a bumble bee hive. We moved the hive into a wooden box with a lid plus 2 openings on each side. We can hear the bees buzzing inside but I’m worried where to put it for the winter. Do I cover the box with rocks, cement or soil? Thanks for your advice! I live in Windsor Ontario Canada, so our winters can be way below freezing. Don’t want to loose our little friends. Thanks again! Marilynn

    • Marilynn,

      The little colony will not survive over the winter no matter what you do at this point. Only newly mated queens will survive, and they will not live in the nest. Each one will go out and find a hole in the ground or in another protected spot and hibernate until spring. The rest of the bees, including the workers, the males, and the old queen, will all perish with the advent of cold weather. In the spring, the overwintered queens each will start a new colony.

  • Hi Rusty, thanks for your response to my query, it is appreciated. I am now developing a new found respect for these little creatures. I just wanted to tell you that the day I wrote my query I had fed up this little bumble bee with quite a lot of sugary water and put him/her in a nice warm sunny spot on my patio. Went back about an hour later and bumble was stretching his/her wings and as I approached buzzed into the air, landed on my arm, buzzed for a few seconds and flew off quite happily. I am hoping that bumble has found a nice warm spot to winter over in and will carry on to produce lots of little bumbles in the future. I have lots of lavender plants and also quite a few Polyanthus plants in full flower (it is the cold season here in the Southern Hemisphere now) as I like at least a little colour in my garden even in winter. I even have a flowering cherry tree in full blossom so these beautiful creatures are reasonably well catered for in my garden most seasons. Thanks again

  • Hi,
    I am in Montreal and have a bumble bee hive under my deck from the summer (it is now September). I left them alone as I am a live and let live kind of guy, and they seem to pretty much ignore us when we are out on the deck, but I did get tagged 4 times by one particular aggravated fellow when I was out cutting the grass 🙁
    Anyway, I am wondering what I can do to discourage them from setting up house there next spring. I don’t mind them in the garden, but I think we just need a bit of distance. I was thinking of opening the deck and removing the hive when it is very cold in November, but from what I am reading that won’t help. Is there any way of enticing the new Queens to a new location in the spring without harming them?

    • Greg,

      A bumble bee colony will not survive the winter in Montreal. In the fall the newly mated queens leave their home and find a place to overwinter. Each individual finds a hole, usually in the ground, about as wide as she is. She will spend the winter there hibernating. The other members of her colony (the workers and the males) will die with the first hard frost. In the spring, the mated females will look for an appropriate nest, usually an abandoned rodent hole or something similar. It is possible someone will select your deck again, but not a sure thing.

      So, after the first hard frost, you can simply close up the hole. No one will be alive in there, so you are doing no damage. Just fill or close the hole somehow so it doesn’t encourage any tenants in the spring. When the queens come out of hibernation, they will have to find a different location to nest.

  • I was starting to remove a large bush near my house today (Late Sept, SE Michigan) and disrupted a group of bumblebees living among the roots. There were almost ten of them and there may be more, and they all looked pretty large to me (i.e. queens). The were at first sluggish but then eventually flew away. Do they have time yet to find new homes? There are a lot of shrubs and trees in my yard and neighborhood. Is there anything I can do to help them out? Thank you! Tom

    • Tom,

      Bumble bee colonies die off in the fall, usually with the first hard frost. I imagine the queens you saw would have moved out within a few days regardless of what you did. Each mated queen finds its own overwintering spot, which is usually a small hole or crevice about the diameter of the bee herself. Each queen, all alone, will hibernate overwinter and then in the spring each will look for an appropriate nesting spot, often a disused rodent borrow or similar hole.

      At this point there is little you can do. But I wouldn’t worry. They will do fine on their own.

  • My husband and I were sitting by our koi pond where some bumble bees were visiting our flowers. Greg asked wonder what they do in the winter and five minutes later you gave us a nice summary of their life cycle – Thanks!

  • Just spotted one locally, it’s the 7th of December. Not sure I’ve ever seen one this late before albeit a very mild 12C today.

  • This is the third year I’ve noticed about 100 holes in my backyard. I think they’re bees how can I stop them from coming?

    • Rochelle,

      You are lucky to have ground bees in your yard. Not only do they pollinate the local plants, but they aerate the lawn and keep it healthy. The holes also allow good moisture penetration. The bees will disappear after about six weeks and you won’t see them again till next year. If we humans would just stop eating, we wouldn’t need bees they way we do, but I don’t see that happening any time soon.

  • Hi I’m in Dunedin, New Zealand and had a delightful find of a nest of bumble bees under my deck in a dry garden with rocks and plants. There are two small holes leading to a space under the concrete driveway. My Mum had just commented the other day that I needed bumble bees in my menagerie too. THEY FOUND ME!

    I have read all your helpful comments and am thinking of setting up a few hives to entice new queens back next year. I am keen to help the environment and am entertained by watching them buzzing into land and taking off again even faster!

    We also have leaf cutter bees available to purchase here but they are quite different. Was wondering whether I should wait for more bumbles next year or buy leaf cutter bees or have both?

    Thanks Paulette

    • Paulette,

      That’s up to you, of course, but it’s easy to do both. They don’t overlap much, so the bumbles and leafcutters will pollinate different things.

  • Oh and this morning I was delighted NOT to find any bees in water, having just educated myself that bees need water and drown. I set up a small bowl filled with rocks and water just below the depth of the rocks near the beehive. So simple and effective. Easy to replace water each night for my wee friends…..

  • Thank you so much for the bumble bee info. I recently moved from a big city (Toronto, Ont. Canada) to a country property (10 acres). I’ve been trying to make what was pretty barren fields into good bee forage. I really appreciate the information you’ve provided. I find bees to be absolutely fascinating creatures.

  • Dear Rusty,

    I’m in the Netherlands and today I found a humble bee inside our house, probably overwintering here and now waking up. I’m a bit reluctant to bring her outside, because it’s around -5 degrees Celsius and a very strong wind – I doubt whether she’ll be able to find/dig/build a good overwintering spot. What do you think? Other options would be to feed her in the house or put her in the fridge until spring arrives and then bring her outside. I’d love to hear your advice.

    Thanks a lot!
    Serek

    • Serek,

      Once your bee broke diapause, you can’t put her back in. However, you may be able to induce quiescence, which is state of lowered metabolism, by putting her in the fridge for a few weeks. Be careful not to let her dry out, however. Wrap her loosely in something like cotton and put her in a tightly-closed container so she doesn’t dry out. When you finally take her out, provide some sugar water.

      Also, let me know the result. I haven’t tried this before.

      • Dear Rusty,

        Thank you for your advice. We have put her into a small box and sits on top of some sawdust, and made a lid out of a transparent plastic foil with openings, and she’s in our garage where it’s 10 degrees Celsius. Would that also be a good temperature? Because then at least the risk of drying out is less big. The bee hardly moves at all; maybe one or two steps a day. So she seems to already be in a state of lowered metabolism. We also have a separate garage outside of the house where it’s 3-4 degrees Celsius, so we could also put her in there.

        • Serek,

          Well, if she’s hardly moving at 10, that’s probably fine. Some species are more active at lower temperatures than others, so I would just go by the amount of movement. If she starts flying around (it doesn’t sound like she will) then I would go colder.

  • Just found a whole row with about 30 bumblebees in my garden, all coming out of cocoon type holes just an inch or two underground. Many buzzed around on the ground for a while and then flew off. Others needed time in an incubator jar I made. Never knew that new queens winter that way. For several years, we have had a single ground nest near our garden, that has provided pollinators forthe garden flowers. Sure hope many of these new queens survive the early spring!!! Thanks for the insights!!!

  • Hi Rusty, I have a bumble bee that I thought was coming back every year and drilling holes in the bottom of my vertical wooden porch railing leaving a little pile of sawdust on the steps. I thought it was the same bee but after reading posts realize it’s a new bee every year? What is the bee doing? This is the 3rd or 4th year. I only ever see one big bumble bee year after year. Very interested! Thank you. Ginger

    • Ginger,

      Bumble bees do not live year-to-year, nor do they drill holes in wood. It sounds like you have a carpenter bee and, yes, they are frequently mistaken for bumble bees. They also do not live from one year to the next. What is happening is the bee is drilling a hole, laying eggs in the hole, and dying at the end of the season. The following spring her offspring emerges from the hole and starts drilling her own holes nearby.

  • Hello Rusty,

    I’m from Long Island, NY and have what appear to be Common Northeastern Bumble Bees going into a hole in my foundation 2″ from the ground right where I have my organic garden. The action is not very frequent, but definitely happening. Noticed them a few weeks ago and contacted the LI Beekeepers org, as I don’t want to kill them, but since they are not honeybees, no one is interested. I am afraid if I leave them there I will have a bigger problem… and fear that maybe they are going into the walls. Money is tight, and I’m considering dusting the entrance. I’m a 61 yr. old female and the fear is getting to me… I read that they will all die when the cold weather returns, but there will be a new brood of queens. If I do nothing, will the queens stay in there? Would I have to remove the hive? I want to seal up the hole. Thank you, Sue

    • Sue,

      The nest will not be reused. The mated queens will find a new place to overwinter and the old nest will be abandoned and you can easily seal it up.

  • Hello,
    I have, what I think are, bumble bees nesting in a bird box, that normally holds chick a dees, on my front deck. They are not an issue, but I’m wondering will all the bees abandon the bird box come winter? After reading the previous post I’m assuming it will be vacated and I will be able to clean it out, but, I’m not 100% sure if it’s the same situation as nesting in a foundation.

    • Marlene,

      Yes, the bird box will be abandoned before winter sets in. The nesting strategy is basically the same for both ground-nesting and cavity-nesting bumble bees.

  • Hi, I have a colony of bumblebees under the cement porch stairs. They have been there all summer and have been no problem. This afternoon there have been 2 or 3 bees flying erractically landing on the lawn and burrowing in the grass then taking off and repeating this. They are very aggressive and are chasing my dogs and people. Actually stung my daughter and the dogs. Meanwhile the other bees continue to come and go from the stairs, seemingly completely seaparate and undistubed by them. What’s going on?

  • Hello!

    I have a question. When is the latest time (month of the year) that we could observe bumble bees in nature?
    Thanks a lot

    • You will see different species of bumbles bees at different times of the year. The earliest ones (for Northern Europe) start appearing very early, perhaps as early as late February, depending on the climate. After that, you will see them all during the spring and summer, and on into the fall. Here in North America, a few of the last ones are still flying. But by the the first of November, give or take, they pretty much disappear for the coldest part of winter. In warmer climates, some are active all year.

  • Dear Rusty,

    I have another question. I’m going to do bumblebee rearing; according to your experience, which one is better:
    – collecting the diapausing queens right now or – wait until spring and collect them after their diapause?

  • We have an enormous amount of bees that build small holes under our porch. Our porch is raised up off the ground about 10 feet. They come back to the same spot every spring and stay for about 4-6 weeks. We just leave them alone and they leave us alone. The amount of bees is getting extremely large. I’ve been reading that the bees don’t return to the same site, however, we have bees every year in this same site. They have returned to this site for about 5 years. They use to cover about 3 feet under our porch with their little holes but now they cover about 12 feet. Is this going to become a problem? We love that they help pollinate our raised vegetable gardens, but they are starting to take over.

    • Karen,

      The bees under your porch are not “coming back” each year. Instead, they are living there all year long. Solitary ground-nesting bees like that are active as adults about 4 to 6 weeks in the spring, during which time they lay their eggs in those holes. The adults die and the larvae or pupae spend the next 10 months down there, and then the emerge in the spring as adults. When it gets too crowded, some adults will move on and begin to dig and lay eggs elsewhere. You are really lucky to have them; they are such cool bees. If you have a close-up photo, I can probably identify them for you.

  • Do not want to exterminate but saw bumble bees going in and out of stones into the crawlspace below foundation. Do not know if they are actually in crawlspace. I have read several comments and wondering what will be left or in the nest over winter. If it is only the queen bee it appears it will leave next spring. Will other bees hatch and hang around in that nest and use it? Am concerned but would like help in understanding.

    • Dave,

      You don’t say where you live, but if you are in a northern state or Canada, no bees will overwinter in the nest. The newly-mated queens will go off on their own, find a hole in the soil, and spend the winter there. The other bees, including the workers, males, and old queen, will die with the first hard freeze. Since nothing will spend the winter in there, it’s a great time to seal up the space, if you can.

      Even though no bees will overwinter in the nest, it is possible a queen who is looking for a nest in the spring might decide to re-use the same space, which is why it’s a good idea to seal the opening.

      If you live in a warm area with no winter freezes, a nest can sometimes persist all winter long.

  • Thank you for your quick response. It was appreciated. We do live in Canada but since they are going into a heated crawlspace and under the foundation I thought they may be toasty warm all winter and was worried the nest may be wintering over. If what you are describing will occur I will wait another month and seal up to the best of my ability. Again thanks.

    • Dave,

      In a cold climate like yours, even if the bees are warm they won’t have a food supply. They don’t store food for winter like honey bees do, so they can’t survive a season with no flowers.

    • Hi Rusty,

      Thanks for all the information on this page. I read through your responses to the questions above and have another.

      We live in southern Ontario and recently noticed bumble bees coming in and out of a hole in the side of our house. We have renovations starting soon to enclose that portion of the house with a small addition. Is there a way to encourage the bees to leave their nest before the first hard frost? Unfortunately, they seem to be in the concrete blocks so there’s no way to access the nest to move the whole thing.

      Thanks!

  • My parents just found that bumble bees are living in a crack in their house. We did some research and discovered that bumble bees are great pollinators so we would like to keep them alive. I am working on convincing them to wait until the queen bee leaves the house to overwinter in the ground, and then they can seal up the house.

    My question is – at what temperature is it safe to assume that the queen has left to start her hibernation?

    Thank you,
    Celeste

    • Celeste,

      First of all, the queen in there now will not leave, she will die along with the workers. The bees that leave are the newly-mated queens. They will each go out and find a place like a hole in the ground to overwinter. The time and temperature at which this all happens depend on which species of bumble bee it is. Certainly, by the first freeze, they will all be gone.

  • I would like to support the bees around my home. I have a line of concrete blocks along the side of a driveway with a garden bed to the side. The blocks are mostly buried in the ground. Is there anything I might do to make the blocks usable for bees to use for overwintering?

    • David,

      If the blocks are hollow you could fill them with hollow stems or handfuls of straw. Or if they are solid, you could drill holes in them. Either of those would work for cavity-nesting bees.

  • I am so lucky having bumble bees around my little garden. I just love these incredible little creatures.

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