If you, a nocturnal insect, knew how to travel in the darkness by navigating with moonlight, a light bulb might be confusing… distracting… irresistible. This NatGeoWILD video explains why something called transverse orientation drives moths to artificial light sources at night:
Next, watch Borrowed Light, On Light Pollution: The End of Darkness, Star Parties In Our National Parks, and A Visual History of Light, animated.
An easy way to think about transverse orientation is to imagine a sailor traveling in the direction of the North Star. In theory, moths similarly follow the light source at a precise position and a precise angle to their bodies. This is how moths would navigate for millions of years… by the light of the moon.
What moth evolution couldn’t account for was the proliferation of constant electric light in our modern world. When Thomas Edison patented the light bulb on January 27, 1880 it was a bad day in moth history. These light bulbs began to act as artificial moons, confusing moths and overwhelming their senses.
Bonus: What’s the Waggle Dance?