Why Do Moths Fly Into Fire, and How Can We Make Use of This Instinct

The idiom "moths flying into fire" is one almost everyone knows well. A moth flying into fire will burn itself to death, so why does it still throw itself in without a thought for its own safety? Let us take a look below at why moths fly into fire.

1. Why do moths fly into fire?

Most moths like to be active at night, and at night moths use light to judge direction. Through scientists' experiments and discoveries, moths mainly rely on moonlight to determine direction when flying at night. A moth's eye is a compound eye made up of many simple eyes, and while it flies the moonlight always projects into its eyes from one direction. When a moth loses its direction, turning its body brings the moonlight in from the original angle, letting the moth find its direction again.

But when there is a lamp or fire, the bright light will likewise project into the moth's eyes, and it mistakes the light for the moon. In this situation, as the moth turns, it finds that the angle of the light has changed, so it keeps circling around the light.

2. How can this instinct of flying into fire be put to use?

A moth flying into fire is an instinct it cannot escape, and this instinct can be used to trap and kill moths. This trapping method is very environmentally friendly and can reduce the use of pesticides. When using light to trap and kill pests, keep these points in mind:

1. Different insects have different requirements for light colour and light intensity, so different lights should be chosen according to the pest to be trapped and killed.

2. Using light to trap and kill pests is easily affected by the weather; generally, the most insects are trapped on muggy nights with no wind, no rain and no moonlight.

3. Using light to trap and kill pests is only effective against those with strong phototaxis; otherwise the effect is poor.

4. Lamps should be installed at the roadside or field edge, where they do not interfere with farming activities and are easy to manage and repair. They should not be set up in warehouses or near dormitories. To get results from using light to trap and kill pests, it should be done over a fairly large area.

If vegetable growers and fruit growers come across some pests, they can make appropriate use of the moth's phototaxis to kill them, reducing the use of pesticides and making vegetables and fruit safer and more reassuring. A moth flying into fire is an instinct, and this instinct can be used to safely eliminate pests.