Flies do not like the smell of citrus oil, cloves or some other herbs like basil or mint. So when you eat outside slice a lemon and arrange the slices on a plate. Then, insert whole cloves into the lemons.

 Don't be stingy with the cloves! If there's lots of food or company, make multiple plates full of lemons and cloves and place them strategically around the barbecue area and on the table or let them float in decorative containers full of water. They’ll look beautiful and smell delicious.