WHY ARE THE FLIES ATTRACTED TO LIGHT?

  Within the range of insects, the Lepidoptera such as butterflies or moths use solar light to find their way around, to feed and even to lay the eggs. Given the nature of these insects, especially of the moths, the lack of light especially during the night forces them to rest or to hide; this is why when we turn on a great light in complete darkness, they think that it is daylight and come to that heat source; if that light turns to be a fire they die. The insects are especially attracted by the ultraviolet light emitted at 365 nanometers, the best wavelength for attracting insects, because it contains radioactive cells that attract them to light energy. The white light attracts these insects, but the yellow light no.

The flying insects are attracted by light.

    Some insects, including the flies, have got a visual organ that in biology is called compound eye.  It consists in hundreds of receptory units called ommatidos with sensory cells that individually distinguish between light and darkness as well as some colours, from ultraviolet zone to orange. The image flies see is a set of multiple ommatidos turn to different directions. The compound eye can detect fast movements and elementary principles of vision.

     Flies, like many other insects, are attracted to light, especially during the night, are immersed in the dark; the contrast between this and light, joined to the fact that the insects are ready to react to showy things, make the attraction much higher.

                                                  The flies' light attraction is used by the exterminators to eliminate them.


     Flies carry some pigments that respond to light called criptocromo - is a light recipient molecule with which they regulate the cardiac rhythm. Simultaneously it regulates the vigil, rest and activity, the body temperature, cardiac performance and other functions. When the animals are exposed to constant and intense light, the heart rate becomes irregular, confusing the night with the day, disorienting the internal biological clock. This insects are called photopositive and the phenomenon is called phototaxis.

Like all the insects, the flies have cold blood and use the light to warm up.

     The science does not have a definite answer to this topic, but with the conducted researches, one believes that an important reason could be to warm up, since they are animals with cold blood and they need heat for living. The majority of the photopositive insects that are attracted by light are nocturnal.