In 2008, there were about 3.5 million kindergarten, elementary, middle and high school teachers in the country, so we can expect almost another 500,000 to be hired by 2018. Also indicative of the high demand for teachers is the large volume of grants available for teachers.
Another option is to mix small amounts of apple cider vinegar with the animal's drinking water; consuming this solution is known to change the blood pH of the horse, thus keeping horseflies away. Cider vinegar, coupled with essential oils, is also used in home sprays as the sharp odor may repeal horseflies.
Screening is an excellent way to keep flies out of feed and tack rooms and box stalls. Fans that direct a downward and outward air flow will keep flies from entering barns. Fly traps and sticky paper will capture flies. They may be most useful as a means of documenting fly numbers over time.