The Tree Flies
This type of Fly is not like other flies in general, who like to perch on food or piles of garbage so common to be a source of disease for humans and impressed disgusting
However, these Flies live in agricultural areas and make young leaves and shoots of plants as food source intake, if the population is much to damage the cultivation of Farmers.
Slightly evil because it will harm the farmer, but such is the consequence of life, when a subject to make a profit there will be an object that is harmed.