Wow. What a nuisance. I'm afraid I don't have a lot of
experience in this area.
A good old-fashioned fly swatter works for me. The old-fashioned
hanging fly strips still work, I believe. As long as they're
hanging high enough to keep out of kids and pets reach, that's what
I'd try.
If you don't get many replies here, I believe I'd google this
topic and see if you can find some good ideas.
Best of luck ridding yourself of the menace.