We’re gonna start this one off with a moth joke, because — why not?

A new study published in Biology Letters by Swiss zoologists shows that urban moths have learned to avoid light.

Under the assumption that natural selection would favor moths with less propensity to fly to light in urban areas, the researchers examined a small moth called Yponomeuta cagnagella. For the experiment they collected larvae in areas with low light pollution, and in areas which have been exposed to heavy light pollution, such as Allschwil or Basel City.

The researchers then analyzed the flight-to-light behavior of almost 1,050 adult moths in the lab. They found that moths from populations that have been exposed to heavy light pollution over generations have a significantly lower propensity to move towards light sources than individuals from areas with low light pollution. Furthermore, the study shows that in both types of populations the female moths were attracted to light significantly less then their male counterparts.

The study results suggest that natural selection has changed the animals’ behavior because flying towards light is disadvantageous for moths in light-polluted areas.

Read more at:

– Reduced flight-to-light behaviour of moth populations exposed to long-term urban light pollution