Fruit flies with black eyes, known as dark-eyed fruit flies, breed more frequently in drains, around bathrooms and urinals, and even in rotting cacti.Fruit flies do not bite, but most people consider them annoying. In hospitals, they are considered a public health risk because of their potential for contaminating sterile surfaces. In addition to bacterial contamination, ingestion of fruit fly-infested food has been reported to cause intestinal upset, diarrhea, or intestinal myiasis. Health departments consider fruit flies in restaurants or other food service businesses to be unsanitary.
Fruit flies can be controlled by taking out the trash or removing unrefrigerated, overripe fruit, or rotting vegetables. Locating and eliminating other breeding sites can sometimes be more challenging. Using traps or sprays may provide temporary relief from fruit flies, but eliminating the breeding site is essential for complete control.