Yellow flies seem to be worse this year than last. In the month of May, the South Walton Mosquito Control District located on Highway 393 N. handed out over 1400 black balls. Come by our offices if you have not already picked up your black ball. One per household, you must reside within our district, please bring proof of residency. Remember yellow flies fly during the daytime and early evening. Other than using mosquito spray with DEET there is not much you can do.