If you're creeped out by bugs, you should probably just stop reading now.
As part of its ScienceTake series, The New York Times posted a video on its YouTube channel Saturday featuring a species of millipede from the genus Motyxia that can glow in the dark. I'm talking "John Malkovich standing at the foot of your bed when you wake up in the middle of the night" level of creepy -- at least for people who already find insects more terrifying than fascinating.
The Times bases its explanations on the work of entomologist Paul Marek of Virginia Tech University and Wendy Moore of the University of Arizona. They studied and wrote two papers about these bioluminescent millipedes that shed new light (pun intended) on how they got their glow and the purpose it might serve.
The first paper, published in the journal Current Biology in 2011, said the glow works as a defense mechanism to warn potential predators that the millipedes wouldn't make a good meal since they also produce deadly cyanide. To investigate the question, they had collected 164 living specimens from the Giant Sequoia National Monument in California and painted half of them to keep them from glowing. They also made some fake millipedes out of clay, half of which they painted with luminescent paint, and placed both types in the California forest to watch how rodent predators reacted to them.
According to the paper, the researchers observed "non-luminescent millipedes being attacked up to four times more often than their luminescent counterparts," leading them to conclude that the bioluminescent glow served as a warning for predators to back off, unless they have a death wish.
Then, in 2013, Marek and Moore found another species of millipede to be in the Motyxia genus when they discovered that it too glowed in the dark. This revelation led them to examine the glowing evolutionary history of these millipedes, which became the subject of a second paper, published in March in the Proceedings of the National Academy of Sciences journal. They wrote that the glow of these millipedes started as a side effect of the "metabolic stress" of producing cyanide. Their glow grew brighter over time as it served as a more effective warning to hungry predators, according to the study.
If you dare, watch the video of this real-life creepy crawler below.