Long before GPS and radio, seafarers relied on the stars to guide them to their destinations. In the animal kingdom, birds and seals have demonstrated a similar capacity for celestial navigation. And now there's one more living creature we can add to the list: The humble dung beetle.
Yes, the feces-eating bug joins more exalted company thanks to new research from Lund University in Sweden. In order to feed themselves and their offspring, male beetles seek out fresh piles of guano, roll some of it into a ball, and quickly push it home with their hindlegs before a competitor can snatch their prize away.
In a previous experiment, neuroethologist Marie Dacke was astonished when she observed beetles seemingly finding their way home at night without any other visual cues readily available save for starlight. Indeed, the path they took home was not just accurate — it was virtually a straight line.
To test if the bugs were using the stars to guide them, Dacke and her colleagues set up a meticulous outdoor experiment. They constructed high-walled arenas to remove all the beetles' visual cues except for the night sky. After leaving piles of dung and sending the beetles out to scavenge, the team discovered that the bugs could correctly orient themselves and push their balls home without any trees, plants, or other terrestrial landmarks. (Repeated experiments indicated the bugs didn't need the moon, either.)
Researchers, in this case, think they're able to accomplish this thanks to special photoreceptors in their eyes. While beetles lack the visual acuity to pick out individual stars, they can see blobs of blurry star patterns, which function as a "good enough" reference point to set their internal compass in the right direction.
THE WEEK'S AUDIOPHILE PODCASTS: LISTEN SMARTER
- How academia's liberal bias is killing social science
- How to be the most productive person in your office — and still get home by 5:30 p.m.
- 43 TV shows to watch in 2014
- Dick Cheney's America is an ugly place
- The liberation of Barack Obama
- The Hobbit: A disappointing set of movies, but a worthy set of prequels
- America is building a Sunni army in Iraq to take on the Islamic State
- The age of miracles is over — even for the religious
- How to make the ultimate grilled cheese
- Diagnosing the Home Alone burglars' injuries: A professional weighs in
Subscribe to the Week