Will Bumble Bees Cause Damage In My Roof?

Here is a query regarding concerns over whether a bumble bee nest would cause damage in a roof.  The answer?  It's highly unlikely that bumble bees will harm any house structures:

The Query:

"Hello I wonder if you can help. Over the last few days a few bumbles bees have been going in and out of a small gap in the eaves of my house. Having looked again this morning, they seem to be establishing a nest as numbers have increased dramatically in the space of a few days.

I had a problem with Honey Bees nesting in the same place last summer - perhaps they are using the same nest? I always have bees in the garden every summer - Honey and Bumble Bees.

The roof space is very small (3ft max) so it's not going to be possible to remove the nest.

I know that Bumble Bees are non-aggressive and would like to leave them be really, but am concerned about them coming into the house (it's a very old property so lots of nooks and crannies!) as the Honey Bees did last year in large numbers.

I really don't want to get pest control people involved as I know they are an endangered species and there are lots of flowers in my garden for them. I'm just worried about potential damage to the building, wiring, that sort of thing.

How large will the colony get? Any advice gratefully appreciated. Thank you."

My response:

"Thank you very much for your email, and your kind concern for the bees.

Bumble bees are nothing to be concerned about.   Their nests are only temporary, and only the new queens survive, mate, then hibernate for winter to start the cycle again next year.  In this way, they are very different from honey bees – a nest of honey bees is a more permanent situation – only part of the colony swarm off to make a new nest elsewhere, and leave the other part of the colony behind in the original nest.  Swarms may of course, rest temporarily, whilst they seek a nesting site.  I always recommend people contact a local beekeeper for assistance with honey bees.

Honey bees have large colonies – perhaps 10 - 20,000 individual bees (that is not a typing mistake), and reaching much more at its peak in a bee hive.  Bumble bees have small colonies, but it depends on success of the colony and species.  Hopefully, the colony will be successful, in which case, you might get between 120 – 300 bees – but it really depends on the factors mentioned.

I wouldn’t be very concerned about bumble bees getting into the house. It’s possible, but it would be an accident, and if it happens, they’ll be looking for an escape route.  You are just as likely to get a bumble bee in the house from an open door or window, as from the situation you describe – possibly more so.  If you get bumble bees in the house, I’d be more than surprised if it was more than 2 or 3, and remember, they only have fairly small colonies.  I would think the nest will be in good view of the ‘in and out’ exit hole for the bees from the roof space.  As long as this remains unobstructed, they’ll find their way out.

Even if they get into the house, and even if they were to stay there:

  • Males and workers would die naturally at the end of the season regardless.

  • Only new queens, if they have had plenty to eat and are ready to hibernate, would be likely to survive in the house.  Even if this were to happen, queens are a very small number of the colony, and only emerge later in the season.  I doubt you’d get more than 1 or 2, if any.
  • Bumble bees do not cause damage to properties at all.

In short, I feel this is nothing to worry about. I am quite envious, because I would rather like to have bumble bees  in my roof.  I have them in the garden (such as this nest I had in my compost heap), but that is it.  Ah well!

Once the nest is finished, and completely inactive (wait until very late Autumn/early winter to be sure) you could clear away any debris.  Wear gloves in case a bee has remained behind.

meme explaining that bumble bee nests can mostly be left alone because they only last a season

John Lewis-Stempel

A review of this beautiful nature diary

John Lewis-Stempel

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