Can Flies Fly in the Dark?
WouterCan flies fly in the dark? That’s a question many scientists have wondered for years. In 1954, Japanese ecologist Syuiti Mori began an experiment by exposing fruit flies to a dark cloth. This experiment continues to this day, and is one of the longest-running in the lab. In the time since, more than 1,500 generations have passed, and scientists have discovered dozens of genetic variations.
The answer to the question of can flies fly in the dark depends on our understanding of the retina. Our eyes are very sensitive to light, but they process it much more slowly when the light level is low. This means that flies have a much lower resolution image of objects than we do. In addition, flies’ eyes are tiny and their heads have only a limited number of facets, so the images they perceive are blurry.
Flies also have a circadian rhythm. This means that they sleep at a certain time, each night, and ideally, they choose a place far from predators. Their nocturnal naps are very short, and they often take refuge on walls, floors, or curtains. During the winter, flies may not sleep as much, and instead flit about in the dark in order to survive. This lack of sleep can have serious consequences. It can cause memory problems and decreased brain activity. This will negatively impact their ability to fly.
Flies are also able to see in the dark. Their compound eyes are made up of many tiny facets that concentrate light onto clusters of photoreceptors. Each of these facets is responsible for producing a pixel in the fly’s vision.
