" The primary threat from flies is the distribution of disease carrying organisms that affect humans such as salmonella food-poisoning, Dysentery, Typhoid Fever, Cholera, Hepatitis, Tuberculosis, Poliomyelitis, various parasitic worms and many others. Some flies (Fruit flies) are pests of fruit and vegetable production and others are internal parasites of livestock. The flying adults primarily conduct these activities." - AEPMA
"Bush flies are annoying to humans because they often buzz to our faces and they cling to our backs, they're actually after our sweat and tears. Our sweat and tears are pretty much like a sports drink, like a Gatorade, to these flies. "- Dr Bryan Lassard
Distraction can be dangerous
When operating high powered machinery, the momentary distraction to wave off bush flies can bring unintended consequences. Flynets can offer some relief at the expense of poor vision when it's needed most.
"Horseflies are notorious for their bite, but it's only the females that bite because they need the protein in blood to ripen their ovaries. It's only a handful of species that bite, the majority of them literally just drink nectar from flowers all day." - Dr Bryan Lassard