TheScullster wrote:

Hi all

I noticed last year that the hole in the front of my bird box had
been enlarged considerably by previous occupants and thought that
this was probably the reason for the lack of recent interest. So I
made a cover plate out of aluminium with a smaller (original size)
hole. This year I had some interest, but decided that the birds
didn't use it because their attempts to alter the access simply
resulted in headaches or bent beaks. So I removed the aluminium
cover plate with the intention of making a wooden ply version. This
I did, but when I went up the ladder recently to fit it I noticed
that there was a nest in the box, but no feathered inhabitants. I
started to remove the lid and noticed that a loud buzzing noise
started issuing from the box!!! Needless to say I descended the
ladder rather smartly and left well alone.

So what has taken over the bird box? I have had wasp issues before
and know how they behave - haven't seen any of those. Despite
frequent glances, I have yet to see any flying insects entering or
leaving.

Anyone know-or-can-suggest the likely culprit?

Almost certainly it'll be tree bees
http://www.bumblebeeconservation.org.uk/tree_bee.htm

That's what moved into our small nest box this year which is less than
6 foot from our patio windows and they havent bothered us at all, just
left them alone.

Mind you the neighbour wasnt too happy as "every time their kid banged
the fence they got aggressive"

Funny that eh?
So I haven't moved them

--
Donnie