I have found an easy cure for this by trying to avoid mosquitoes. You can buy a simple bottle Eucalyptus oil. Insects hate it. It beats any mosquito repellant I have ever seen and. flies just stay away. I put it in my hair and beard for mosquitoes, and found the flies also stay away. If you have a fan in your shop you can soak a cotton ball or small rag in it and attach it to the fan and it will fill the room with a very pleasant odor that insects hate. We have livestock in the fields around us, and flies can sometimes be a real nuisance. Not enough rain here for many mosquitoes in quite a while.
Where there's a Willis there's a way!