Why Are Flies Attracted to Light?
WouterThere are a variety of theories about why flies are attracted to light. They may find it useful as a navigation aid or as a way to avoid predators. The fact that light reflects from certain surfaces makes them an attractive lure. Insects also associate light with safety, as most light sources are located high off the ground and away from potentially hazardous environments.
Insects also show preference for certain wavelength bands. Among these are UV, green and blue. In addition, the contrast between light and background is critical. Studies on the visual attraction of biting flies found that ambient lighting and surrounding vegetation can affect the attractiveness of light. For example, a green cloth was less attractive against a green background than a red one. In contrast, a white trap was highly attractive to flies even in the dark.
Light is also essential for insects, as it serves as a compass. Flying north, for example, uses natural light to judge direction. However, to use the light in the north, the light source must be steady and far away from the fly’s path. A porch light positioned too close to the light source confuses insects.
Flies are naturally attracted to light. They also have a large number of neurons. One fruit fly has approximately one hundred thousand neurons in its brain. Flies are also omnivorous, feeding on fruits, vegetables, animal secretions, decaying organic matter, and blood. The larvae of these insects lay their eggs in decaying organic matter and animal waste.
