“Dung beetles steer by starlight” is the headline of a recent article in Science News; the subtitle is Nocturnal insects orient using Milky Way, experiments show.
Will wonders never cease? First, there’s the wonder that beetles use celestial navigation. Instead of using landmarks like rocks and trees to orient themselves, they orient themselves by the sun and the moon, by the patterns of polarization in sunlight and moonlight. And now some enterprising scientists have learned that beetles also use the Milky Way galaxy! Researchers found this out by doing outdoor experiments
blocking the insects’ view of the heavens with blinders or using high-walled arenas that allowed them to see nothing but sky. The beetles could orient when they could see the band of light mady by the Milky Way but not when they could see only terrestial landmarks.
Nearly as wondrous is that scientists discovered this—and by fitting blinders onto dung beetles!
Imagine you’re a grad student in entomology home for the holidays. Friends and relatives ask what you’ve been up to. You pause and reflect on your dignity, then smile in resignation as you decide to bestow on your loved ones the precious gift of laughter. You then describe the challenges of designing, fabricating and fitting blinders onto beetles. You wax eloquent, emphasizing the marvelous juxtaposition of high (the Milky Way galaxy) and low (the beetle) that your work involves. Truly this is a marriage of heaven and earth, you conclude, yet another sign that all things are connected. Funny how you neglect to mention that the particular dung beetles you’ve been, um, handling spend their lives rolling shit balls away from competitors and predators. When your keen father-in-law asks what kind of beetle you’ve been studying, you stay on the high road and answer: Scarabaeus satyrus.
The article ends with a rather bizarre comment from a researcher. “The beetles don’t steer by the Milky Way with a person’s understanding, says Paul Graham of the University of Sussex in England. The blur of stars is just a stable feature for orientation.” Is he trying to reassure us? With what understanding do you steer by the Milky Way?