CLOSE
Original image

Why Are Moths Drawn to Flames?

Original image

Around the world, moths make kamikaze dives into light bulbs and open flames with such regularity that they have their own idiom. What is it about lights that make moths so crazy?


For a long time, scientists blamed the moon. Moths used the moon as a navigational beacon, it was argued, keeping it at a constant angle to their direction of travel in order to fly straight. Light sources used by humans, whether they’re campfires or porch lights, threw a monkey wrench into this system. The moon is far enough away that the angle between it and a traveling moth isn’t going to change much, even after the moth flies a great distance. With a closer light source, though, the angle changes considerably after only a short distance. A moth confusing a light bulb or candle flame for the moon, the hypothesis went, would notice this change and attempt to correct its path by turning toward the light. After just a few course corrections, the moth would set itself into a tightening death spiral towards the light and eventually crash into it, either going down in flames or thwacking its poor little head.

On Second Thought...

Over the years, various holes were poked in this hypothesis. For one—and this is a big one—moths might not even use the moon for navigation.

There isn’t much evidence for it, especially when it comes to the over 50 percent of moths that don't migrate and wouldn’t have much use a celestial navigation aid in their short distance travels.

There’s also the fact that moths don't always circle around lights in a closing spiral like the moon hypothesis assumes. Most of the time, they actually head straight for it. Henry Hsiao, a professor of Biomedical Engineering at the University of North Carolina, has tracked moth flights as the bugs headed toward a light source and found that, most of the time, they fly in a straight line toward the light until they get very close, then veer off and circle at a steady distance.

Hsiao’s observations led him to develop a new hypothesis. He’s unsure what causes the moth to make a beeline to a light, but thinks that the circling behavior at close ranges is caused by a visual distortion common to all sighted creatures called a “Mach band.” The band is the region surrounding a bright light that is perceived as being darker than any other part of the sky. Hsiao thinks that moths hang out in the band because they want the cover of darkness for safety, and wind up circling the light until their flight path takes them away from the it (or causes them to crash into it).

Love Hurts

Another explanation, proposed by U.S. Department of Agriculture entomologists in the 1970s, is that the infrared light spectrum emitted by candle flames contains some of the exact same wavelengths of light given off by female moths' luminescent pheromones. In other words, it’s just male moths that are attracted to flames because they wrongly assume that they’re going to get lucky. This doesn’t explain their attraction to UV light, which doesn’t emit the same light wavelengths as moth pheromones, but it does say something very profound about the lure of love.

Original image
iStock
arrow
science
Unfazed by Haters, This Bug-Loving 8-Year-Old Helped Author a Scientific Paper
Original image
iStock

Sophia Spencer's passion for insects felt perfectly normal to her and her mom. But some kids in the Canadian second-grader's class disagreed, and they didn't make an effort to hide their disgust from Sophia. "She is often teased at school by her peers because she will proudly display her current bug friend on her shoulder," her mom Nicole wrote in a letter that was widely shared on Twitter. But instead of letting bullies discourage her, Sophia held on to her love of all things creepy-crawly. That dedication has since paid off: At just 8 years old, Sophia is now the co-author of a scientific paper published in an entomology journal.

According to Science Alert, the story started when Nicole Spencer wrote to the Entomological Society of Canada (ESC) in search of a mentor to support her daughter in pursuing her hobby. "She has asked me for over a year if this is a job she can do one day, exploring and learning more about bugs and insects. I have told her that of course she could; however, I am at a loss on how to continue to encourage her in this field of science," she wrote. She then went on to ask if there were any entomologists willing to talk with Sophia about bugs and how to turn her passion into a career, writing, "I want her to know from an expert that she is not weird or strange (what kids call her) for loving bugs and insects."

The response was overwhelmingly positive. ESC shared Nicole Spencer's message on Twitter, calling on entomologists to reach out so they could be connected with Sophia. Bug-studying scientists replied with offers of books, supplies, and email addresses for sharing advice. Entomologist Jessica L Ware wrote, "she can contact my lab anytime! We are happy to send her papers, nets, whatever will keep her entomology passion going!" Another reply came from ecology professor Julia Koricheva: "I've been that girl, became an entomologist & still proudly wear bugs on my shoulder."

The tweet was so successful that it's become the subject of its own scientific publication. The paper, titled "Engaging for a Good Cause: Sophia's Story and Why #BugsR4Girls," appears in a science communication edition of the entomology journal Annals of the Entomological Society of America. In it, lead author Morgan Jackson—who sent out ESC's original tweet enlisting help for Sophia—writes about the impact Sophia's story had and how social media can be used as a tool by scientists. Sophia herself is listed as a co-author, and her section affirms that bugs are indeed awesome. "My favorite bugs are snails, slugs, and caterpillars, but my favorite one of all is grasshoppers. Last year in the fall I had a best bug friend and his name was Hoppers," she wrote.

Sophia also describes how the project made her feel more confident about her love of bugs. "It felt good to have so many people support me, and it was cool to see other girls and grown-ups studying bugs. It made me feel like I could do it too, and I definitely, definitely, definitely want to study bugs when I grow up, probably grasshoppers," she wrote. Sophia has even managed to open the eyes of some of her peers since going viral: "I told my best friend and her sister about bugs, and now they think they're cool, and her sister will pick up any bug! I think other girls who saw my story would like to study bugs too."

[h/t Science Alert]

Original image
iStock
arrow
science
2017 Ig Nobel Prizes Celebrate Research on How Crocodiles Affect Gambling and Other Odd Studies
Original image
iStock

The Ig Nobel Prizes are back, and this year's winning selection of odd scientific research topics is as weird as ever. As The Guardian reports, the 27th annual awards of highly improbable studies "that first make people laugh, then make them think" were handed out on September 14 at a theater at Harvard University. The awards, sponsored by the Annals of Improbable Research, honor research you never would have thought someone would take the time (or the funding) to study, much less would be published.

The 2017 highlights include a study on whether cats can be both a liquid and a solid at the same time and one on whether the presence of a live crocodile can impact the behavior of gamblers. Below, we present the winners from each of the 10 categories, each weirder and more delightful than the last.

PHYSICS

"For using fluid dynamics to probe the question 'Can a Cat Be Both a Solid and a Liquid?'"

Winner: Marc-Antoine Fardin

Study: "On the Rheology of Cats," published in Rheology Bulletin [PDF]

ECONOMICS

"For their experiments to see how contact with a live crocodile affects a person's willingness to gamble."

Winners: Matthew J. Rockloff and Nancy Greer

Study: "Never Smile at a Crocodile: Betting on Electronic Gaming Machines is Intensified by Reptile-Induced Arousal," published in the Journal of Gambling Studies

ANATOMY

"For his medical research study 'Why Do Old Men Have Big Ears?'"

Winner: James A. Heathcote

Study: "Why Do Old Men Have Big Ears?" published in the BMJ

BIOLOGY

"For their discovery of a female penis, and a male vagina, in a cave insect."

Winners: Kazunori Yoshizawa, Rodrigo L. Ferreira, Yoshitaka Kamimura, and Charles Lienhard (who delivered their acceptance speech via video from inside a cave)

Study: "Female Penis, Male Vagina and Their Correlated Evolution in a Cave Insect," published in Current Biology

FLUID DYNAMICS

"For studying the dynamics of liquid-sloshing, to learn what happens when a person walks backwards while carrying a cup of coffee."

Winner: Jiwon Han

Study: "A Study on the Coffee Spilling Phenomena in the Low Impulse Regime," published in Achievements in the Life Sciences

NUTRITION

"For the first scientific report of human blood in the diet of the hairy-legged vampire bat."

Winners: Fernanda Ito, Enrico Bernard, and Rodrigo A. Torres

Study: "What is for Dinner? First Report of Human Blood in the Diet of the Hairy-Legged Vampire Bat Diphylla ecaudata," published in Acta Chiropterologica

MEDICINE

"For using advanced brain-scanning technology to measure the extent to which some people are disgusted by cheese."

Winners: Jean-Pierre Royet, David Meunier, Nicolas Torquet, Anne-Marie Mouly, and Tao Jiang

Study: "The Neural Bases of Disgust for Cheese: An fMRI Study," published in Frontiers in Human Neuroscience

COGNITION

"For demonstrating that many identical twins cannot tell themselves apart visually."

Winners: Matteo Martini, Ilaria Bufalari, Maria Antonietta Stazi, and Salvatore Maria Aglioti

Study: "Is That Me or My Twin? Lack of Self-Face Recognition Advantage in Identical Twins," published in PLOS One

OBSTETRICS

"For showing that a developing human fetus responds more strongly to music that is played electromechanically inside the mother's vagina than to music that is played electromechanically on the mother's belly."

Winners: Marisa López-Teijón, Álex García-Faura, Alberto Prats-Galino, and Luis Pallarés Aniorte

Study: "Fetal Facial Expression in Response to Intravaginal Music Emission,” published in Ultrasound

PEACE PRIZE

"For demonstrating that regular playing of a didgeridoo is an effective treatment for obstructive sleep apnoea and snoring."

Winners: Milo A. Puhan, Alex Suarez, Christian Lo Cascio, Alfred Zahn, Markus Heitz, and Otto Braendli

Study: "Didgeridoo Playing as Alternative Treatment for Obstructive Sleep Apnoea Syndrome: Randomised Controlled Trial," published by the BMJ

Congratulations, all.

[h/t The Guardian]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios