On Wed, 15 Jun 2011 16:09:27 +0100, Gordon H wrote:

Should I let them be, or get it removed?
I know they are supposed to be good for the garden, but...

Are they going to become a nuisance? Is their flight path to/from the
nest across a route that is used a "fair bit"? As they are good for
the garden I'd leave 'em alone provided they are out of the way.

No need to get a man in to deal with it should that be required. Just
get some pyrethroid based insecticidal powder, wait for a cool
evening when they have stopped flying and liberally dust the entrance
and nest. 24 to 48 hrs later they will be dead and you can clean out
the box, marveling at their constructional skills.

--
Cheers
Dave.