Allotments 4 All

Every year we seem to get a large amount of these things which I have been told are thunder flies.
Little blighters are everywhere and there seems to be nothing that helps to keep them at bay.
Is there any help out there which can stop or help keep them away from me and the family?
I find them a particular problem when I am on the PC as I try to type the words and they have to land on me. In my ears, on my face and all over my head.
Grrr they really get my goat.
They are to small to squish and there are to many of them to do anything about.
Only see them when the humidity is high so I hope for some rain to get rid of them.