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Where do Bumble Bee Queens Overwinter? Participate in Queen Quest This Fall to Help Us Find Out!

By Victoria MacPhail, York University on 12. October 2021
Victoria MacPhail, York University

Queen Quest returns this fall in an effort to gain information about where bumble bee queens overwinter. The official blitz date is Saturday, October 16, 2021, but you can search before or after this date. You can also submit anecdotal or incidental records of overwintering queens you may have found.

Did you know that bumble bees are an annual species? Colonies will produce new queens and males at the end of summer, which then mate. The newly mated queen will leave the colony to overwinter, while the rest of the colony dies off. She will emerge in the spring, find a new nest site, and start laying eggs to raise a new generation of workers, before the cycle repeats itself. However, while we know a lot about what types of flowers bumble bees like, we know very little about where these new queens go to overwinter. This is a critical data gap we need to fill in order to increase effective conservation efforts. So far, data assembled from past Queen Quests have been useful to support a few ongoing projects—deeper investigations into overwintering depth, planning the details of species status assessments, and studies digging into the details of bumble bee biology.

Some people have reported finding queens in loose soils, mossy ground, leaf litter, near tree trunks or walls, and one species has been seen digging into lawn sod, but we don’t know which approaches are more common, or what approach is best to try and find them. This is where you can come in! Put together a team (4 people is best), find a site with lots of well composted soil or dense leaf litter, and slowly excavate the area. Report your location and search details, regardless as to whether you find a queen or not—absence or “zero” data are just as important as presence data! For more details, including a full protocol and photos, check out


"ruler, measuring, science, conservation, bumble bee queen"
Measure the depth of your excavations and the depth at which you find a bumble bee. (Photo:

Do you have incidental observations (e.g., you dug one up in your garden last year, found one when you were transplanting a shrub)? Please report them to the website here, too! Thank you for your efforts in helping us understand more about these beautiful and important pollinators.


"leaf litter, overwinter, bumble bee life cycle, science, conservation"
Bumble bee queen found in the soil beneath a layer of litter. (Photo: Xerces Society / Emily May). 


Further Reading

For more information about how to help fill the data gap about overwintering bumble bees, visit

Want to know more about behaviours of queens looking for an overwintering site? Watch this YouTube playlist of digging bumble bees.

Read further articles about Bumble Bee Watch

Quick read: Learn about bumble bee conservation from this brochure.

Long read: For a deeper dive into protecting bumble bees, read these conservation guidelines.



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