Ever wondered why artificial lights attract insects at night? And I’m not talking about ultraviolet light, that’s another story altogether, I’m talking about normal lights, which seem to always have a whole bunch of insects circling them constantly. This is a rather multi-layered situation to explain, we will first have a look at nocturnal insects, then diurnal ones.
Firstly, we must ask “how do nocturnal insects find their way around at night?” Well, this is an amazing feat of nature where they use the stars, planets, or the moon! Usually choosing the brightest and most obvious celestial light source, the insect uses this as a reference point and keeps it in a fixed position, so that it can fly in a straight line. For example, if the light source comes from the east and the insect wants to fly north, it would put the light on its right-hand side and fly north, keeping the light source on its right, it will continue to fly north in a straight line. Celestial light sources are so far away that their movement is too slow for the insect to have any trouble flying in a straight line for short periods of time. But if the insect was to choose an artificial light source as its point of reference, thinking this light was in the sky, it would then end up flying in a circle, because its navigation system believes the light should be in a relatively “fixed” location. Without realizing what’s going on the insect then ends up getting closer and closer to the artificial light, flying in constant circles.
Now let’s talk about diurnal insects and light at night. If a light is bright enough it will wake an insect up, thinking it is daytime and time to be active. But the light is surrounded by darkness, so the insect believes it needs to get “outside”, so flies towards the light.
Julien is French and Scottish, born in 1988 in Nairobi Kenya.
He's a professional Nature Guide and Trails Guide speaking both French and English. He has been lucky enough to have worked in some of the most amazing destinations Africa has to offer, from East Africa to Southern Africa, as well as some time in Central Africa.
From a very young age he knew he needed to work with animals, big or small, and somewhere in nature. He was always picking creatures up and trying to see the world from their perspective, trying to understand them as much as possible, mesmerised by their shapes and colours. He liked to share this passion with everyone around, always trying to get them involved in his discoveries. Nature is all around us, in Europe, Asia or Africa, all we have to do is realise it.