First, a dung beetle factoid you might not know: Scientists believe that they navigate at night using the visible portion of the Milky Way — that gorgeous strip of stars and dust that appears in a sky sans light pollution. Unsurprisingly, the finding that dung beetles stare at the stars was honored with an Ig Nobel Award — a prize that singles out research that seems too ridiculous to be true.
But that tongue-in-cheek recognition didn't deter Marie Dacke and Emily Baird of Lund University. They and others have continued to study dung beetle navigation, and they believe their new research shows that the icky insects have a very unique skill.
When a dung beetle finds its namesake, it rounds the precious poo up into a ball, does a funny little dance on top of it, and hightails it out of the area.
"They have to leave the place where the dung pile is, because it's dangerous," co-author Basil el Jundi told The Post. "Other beetles have the same aim, you see, so they might steal the dung."
So the beetle dances around on its little ball, seemingly orienting itself, before setting off in a perfect straight line.
"They will maintain this straight line until they find a suitable place for underground consumption of their dung," el Jundi explained. "Because the straight line is the best way to ensure they escape fast and don't accidentally come back."
When the research team showed that the beetles seek out the Milky Way's light at night, they did so by testing the bugs in a planetarium where they could control the appearance of stars and moonlight. In the new experiment, they used an artificial sun and sky to change variables like the position, polarization and spectrum of light to figure out what cues the beetles needed to stay oriented.
El Jundi and his colleagues initially thought that the beetles might be making complex calculations — figuring out where they were in space based on light and other cues. But they think their results point to something more passive: When researchers hid cues during the dance but displayed them once the ball got rolling, the beetles were disoriented. But when the cues were present during the dance and hidden during the actual journey, the beetles maintained a straight line with ease.
If the beetles were consciously calculating what the visual cues meant, the scientists reasoned, they could make those calculations at any time. Instead, they might be creating a mental image of the position of certain celestial cues during their dance, then simply comparing that mental image to the position of the cues in the sky as they moved forward.
"There's no understanding of what the cues mean in this method," el Jundi said. "It's as if they take a snapshot of all these celestial cues and then match them to the prevailing visual scenery in the sky as they move."
In future experiments, el Jundi wants to figure out just what part of the brain this "picture" is stored in, and how that process works. He'd also like to understand how the physical movements of the pre-rolling "dance" might relate to the process of "taking a snapshot."
He thinks that even folks unswayed by the charisma of the dung beetle should be interested in his team's research.
"If you want to understand a computer, you start by understanding a very simple one," he said. "We could use this to understand similar, more complex systems."
He can even imagine insect navigation techniques being used to inform the programming of self-driving cars.
"This is not my personal aim," he said, "but you could use these systems to design a car that can navigate its environment using similar cues."