We humans like to think we're so much smarter than everything else inhabiting the earth. What with our massive cities and technological achievements, I guess it's understandable. We can even use the stars as a guide, though I don't know how many of us can actually do that well.
I know I can't, which makes me a little sad. Because the dung beetle can.
Granted, most of the time dung beetles use the moon to guide themselves as they roll dung across the African plains. However, as we all know, sometimes the moon just isn't shining. An international research team has discovered that when it's not, dung beetles use the Milky Way to steer themselves in the right direction.
So how does anyone end up studying the relationship between dung beetles and navigation via the starry night? Researchers were first intrigued by the possibility when they discovered that the insects were able to roll their balls of poop in a straight line even on moonless nights. Scientists looked up and theorized the bugs had to be doing it via the sky.
Moving in a straight line is important, you see, because the faster the beetle can roll its dung ball away from its source, the safer it will be from other, potentially bigger and scarier, bugs.
To test out their hypothesis, researchers tracked the beetles as they rolled their poop through the dark night. The beetles were able to roll their balls in straight lines when the moon was out and also on moonless nights when the Milky Way was visible. On cloudy nights, the beetles couldn't roll in a straight line; when scientists taped up the insects' visors so they couldn't see the sky, they didn't really do much of anything except wander around.
Further experiments showed that the bugs couldn't get by using any stars, either. Tests conducted in a planetarium showed that a few bright stars didn't help the dung beetles very much, and that they needed to Milky Way to be visible before rolling could be done effectively.
The lead author of the study, Marie Dacke, noted that the beetles essentially need the celestial systems to navigate, as they basically ignore any other method of determining location.
"Celestial compass cues dominate straight-line orientation in dung beetles so strongly that, to our knowledge, this is the only animal with a visual compass system that ignores the extra orientation precision that landmarks can offer," she said.
On the other hand, trust a GPS to drive a man to his death. That's called technology.