Dung Beetles Use the Milky Way for Navigation

Andi Gentsch via Flickr// CC BY-SA 2.0
Andi Gentsch via Flickr// CC BY-SA 2.0 / Andi Gentsch via Flickr// CC BY-SA 2.0

In ancient Egypt, the lowly dung beetles that rolled turd balls across the desert were the inspiration for the scarab-faced God Khepri, who rolled the sun across the sky each day. Relating these insects to celestial bodies may seem a little generous today, but perhaps the Egyptians weren’t too far off. We now know that dung beetles are one of the few species that use the sun, the moon, and the stars to navigate themselves. 

When a dung beetle finds a prime piece of feces it wants to take back home, it carves it out with its chisel-like head and uses its legs to form a smooth sphere. It transports the ball by basically doing the insect equivalent of a handstand and pushing it backwards with its hind legs. As you can imagine, steering yourself in the right direction in this position gets tricky. Moreover, beetles steal poop balls from each other, so it's in a beetle's best interest to move in a straight line away from the poop source as efficiently as it can.

That’s why before beginning its journey, the dung beetle climbs on top of its poop ball and does a little “navigation dance.” Depending on whether it's a nocturnal or diurnal species, the beetle takes a look at the sun or moon and calculates its internal GPS based on the position in the sky. Dung beetles have even been recently proven to use the Milky Way galaxy for navigation, making them the only known species to do so. Though their eyesight isn’t strong enough to make out specific constellations, dung beetles can recognize the Milky Way’s gradient of light to dark and use it to find their way home. 

Scientists discovered this behavior by strapping tiny hats onto dung beetles to see how it affected their navigation skills. Without the Milky Way to guide them, the beetles were suddenly lost and stumbling aimlessly through the dark. When the hats were removed, the bugs went back to being master navigators.

Even when they do come across an obstacle in their path, all the dung beetles need to do is hop back on top of their prized turd, do the orientation boogie, and get back on track. For anyone who thinks dung beetles are dull, disgusting creatures, this behavior shows that at least they’re not dull.

[h/t: National Geographic