This spring brought a huge swarm of Carpenter / Wood Bees, Wasps and Bumble Bees into our barn. I started spending a great deal of time with a tennis racket swatting at and missing the invaders. I thought there had to be a better way, so, to Google I went.
I found swatting, wood puttying and chemicals to be the remedies of choice. On one forum, somewhere, I read that Wood Bees don't like noise. Since I didn't want to stand out in the barn and yell all day everyday, I plugged a radio in, turned on Rush Limbaugh and cranked his volume up.
The results were immediate, not only do Wood Bees not like Rush Limbaugh but Wasps and Bumblebees don't like him either. They also don't like Sean Hannity, music, sports or advertising. They don't even like liberals but since I have to listen to this also, I haven't tested the liberal theory very extensively.
I haven't seen many flies either but have seen a few, so the jury is still out on fly prevention.
The downside of this for me is having to have the radio on all day. I prefer peace and quiet but certainly don't like the damage that Wood Bees do and I hate Bumblebees and Wasps. So, there you have it, you can't have everything and sometimes you can't have nothin', get over it!