I'm a believer!
Ok, so ya hang a couple of zip lock bags full of water with a few pennies in them on the doorways of your studio or home and it'll keep the flies out. Well when at Pinecroft if I walked outside the deer flies, house flies and flying critters ate me alive. Inside the studio with doors and windows wide open there wasn't a bug to be seen. Brenda even Scotch taped a few pennies on the outside of the bags. It's got something to do with light refraction, prisms and such. http://animals.howstuffworks.com/animal-facts/water-bags