What could they bee???

Not sure what these little buzzing creatures are: Bee, Wasp, Hornet or something I haven't thought of!  They are buzzing very actively round the outer corner of the utility room!  They haven't reached the inside I'm glad to say.  One was caught in my hair as I was standing on a chair to get the shot, but I managed to free it with no harm to either of us!  They are bringing stuff to the 'nest' as you can see!  What is becoming derelict to us is a very busy construction site to them!  So I thought this might be ok for Derelict Sunday this week - it's week 52!!  Many thanks to Freespiral for hosting!

The vaguely pink brick  is to remember to to click on this Link and click on the big pink bar to support breast cancer research and offer someone a free mammogram as it's Breast Cancer Awareness Month! Thank you so much!

Any advice from those in the know would be greatly received!