Moths Just Trying To Orient Themselves

Science gets around to why moths act bonkers around lights:

The insects are not actually drawn to the glow like “moths to a flame,” as the old saying suggests, but rather trapped in a disorienting orbit around the artificial light, scientists reported in a study published January 30 in the journal Nature Communications.

By using motion-capture cameras — and filming with infrared illumination so as not to disrupt the creatures’ vision — the researchers showed that when the insects flew around a light source, they were tilting their backs toward the light and keeping their bodies in that direction. By maintaining this orientation, the hapless critters created odd orbits and steering patterns, according to the study.

...When artificial light does not interfere, nocturnal insects keep their backs pointed toward whatever direction is brightest, which is typically the sky versus the ground. 

This evolutionary trick has helped the critters know which way is up and keep them level during their night flights. However, when the insects pass by an artificial light source, they become disoriented, believing that the human-made lighting is the sky, said co-lead study author Samuel Fabian, an entomologist and postdoctoral researcher at Imperial College London’s department of bioengineering.