If you ever sit outside on a summer’s night after a barbecue and watch the havoc around a light as moths and midges bash off the hot illumination and ask why they do that! Worse again, watch as a moth appears to commit suicide as it carriers into a burning candle flame and inflicts a painful and certain death upon itself.
There is an explanation for this and it has to do with the insect navigation. The compound eyes of an insect contain lots of optical tubes radiating out from the centre of the eye. The insect uses the light from the sky as part of its navigation. Light hits specialised eye cones at an angle of 30 degrees and the insect uses this light to travel in a straight line.
Our six legged friends have been around for millions of years and artificial light has only been around for around 50,000 years. When a moth sees an artificial light it throws its navigation out of sync causing it to fly around the flame in a spiral till the circle gets tighter and then in the case of a candle woof he goes up in flames!