A misunderstanding?

I got stung by what I think was a hornet.

We made compost this morning and after we had finished I walked over to one of the compost bins to tie the gate on.  Suddenly I was attacked by several insects which looked like hornets, but I suppose could have been bees or wasps.  They flew at me in a straight line one behind the other and the one in front bit me on the knee.  This seemed to be the signal for all the others to then turn around and go back from whence they had come.

I am sure I hadn't disturbed them as they flew out from the compost bin and then attacked me as I walked towards it.  Pierre said he thought that probably they had misunderstood my intentions and bit me as they thought I was going to attack them!  I'm grateful that only one of them bit me, as the bite was quite painful when it happened although it didn't stay red and swollen for very long.