It’s a natural thing to consider the housefly a nuisance. It makes an irritating buzzing sound; it annoys you when it crawls on your skin; and so on. For ages that’s what man considered the fly to be just a nuisance.

It was not until the twentieth century that we found out that the innocent-looking housefly is one of man’s worst enemies. It was discovered that these flies carried disease germs that cause the death of millions of people every year!