For centuries man and fly have been at odds. The fly has always been a pest to both humans and animals. It is a carrier of various diseases, some of them lethal.
The presence of manure in poultry and livestock facilities make an efficient factory for fly propagation. As agriculture followed industry into mass production, the fly
prospered accordingly.
About mid-century, a new weapon against flies emerged, insecticides. Suddenly the near-universal tolerance of flies as a fact of life disappeared when the new chemicals
showed their ability to eliminate fly populations.
However, after several decades the fly has developed a natural resistance to most of the legal insecticides, therefore rendering them ineffective.
