Bumble Bees - not quite "In The Garden"

[GeeTee]

I'm putting this in the Garden section as it's about bees and I think it's the best place for it, but the question is not particularly about the Garden at all.

I have a veritable army of big bumbly bees coming and going from an air brick (underfloor ventilation - Victorian terrace) - fat, slow moving black and dark orange bodied things. They've clearly set up home under there as in the late evening I can hear the low buzzing droney noise of them coming through the lounge floor.

I've no problem with them, they're completely docile - I've had them land on me in the garden and caught the few that have ventured into the house in my hands as they mindlessly butt into windows and carried them back outdoors, no stings yet.

The question is more about if any harm could come to the sub floor structure of the house having them in there? As far as I can tell from my limited seaching they just attach their nest constructions to joists or floorboards rather than consume them.

Could their construction block the air brick and compromise the underfloor ventilation? (One front air brick, one rear).

I'd really rather leave them alone as they seem harmless and are an amusing spectator sport when having an evening beer outside with their apparent haphazard navigation.

 

[jay679]

No, they don't cause harm, are highly unlikely to block the vent as the nest will probably be some way in, attached to a joist (hence why you can hear under the floorboards. In any case, the nests are usually very small and only last a few months and are then abandoned when the queen leaves. They are not re-used (although another queen may well find the site again another year.
Just leave well alone.