In a similar situation, I used the foamy spray wasp nest killer stuff.
A little bravery and a lot of common sense is needed in applying it though
!

Pete

I also suggest wearing a pair of stout running shoes, just in case! As a
child I accidentally put my foot into an underground wasp nest while playing
under a bush - I had scores of stings from head to foot. They didn't take
kindly to having their home demolished, albeit accidentally and chased me
for at least 100 yards!
--
David
.... Email address on website http://www.avisoft.co.uk
.... Blog at http://dlts-french-adventures.blogspot.com/