Dear Hiver,
Fly has a varies species and color also the variety of animal that has the same classification in nature, the existence of this animal was always seen as the harm animal, it is due to many insecticide produce to eradicate this animal, but fortunately it has fantastic number in their life cycle, so the balance and the existence still maintain, today I found housefly perch on the leaf I try to get close to capture the reflector of this fly. But it seems difficult to capture it, it is due to the unstable move of this fly.
Fly also include in the food chain of nature, reducing the population of this animal, absolutely will endanger the existence of other food chain cycle.
The wise action that can be done, is controlling the number of population by sectorize or localize the existence of fly
@faizarfatria