YOU might have heard of the saying, “like a moth to a flame”.
This idiom is commonly used to describe an instinctual, irresistible attraction that often results in self-destruction, referring to how moths seemingly commit suicide by flying into fire.
Are moths actually lured to flames despite the apparent danger?
Verdict:
False
Moths are not attracted to fire and other dangerous light sources, so much as they are disoriented by it.
These poor bugs have a bad reputation for flying straight to their demise, but moths and other lamp-attracted insects are simply following their biological navigational systems.
According to National Geographic, flying insects have evolved to travel by a fixed light source, such as the sun or the moon, via a mechanism known as transverse orientation.
As Jeff Smith, curator of the moth collection at the Bohart Museum of Entomology, explains, moths orient themselves by keeping their bodies at a certain angle relative to the moon – the main source of light found in nature before humans invented light bulbs or learned to use fire.
This is similar to how explorers of yore navigated using the North Star as a reference point prior to the invention of the compass and other modern navigational tools.
As such, a human-made light source such as a light bulb or burning candle essentially looks like an artificial moon to a moth.
According to Lynn Kimsey, a professor of entomology, moth eyes are also tuned to the faint light emitted by celestial bodies. Thus, powerful artificial illumination can act as a very confusing “super-stimulant”.
Disoriented moths inevitably find themselves circling artificial light sources in endless loops as they attempt to orient themselves to the “moon” until... zap!
This biological mechanism is exploited by insect light traps.
All in all, what was once a useful navigational system has turned into many a moth’s ultimate downfall. It’s too bad that moth evolution didn’t account for Thomas Edison.
Sources:
1. https://www.nationalgeographic.com/animals/article/moth-meme-lamps-insects-lights-attraction-news
3. https://www.sciencefriday.com/articles/why-moths-are-attracted-to-light/
