CLOSE
Original image
Andi Gentsch via Flickr// CC BY-SA 2.0

Dung Beetles Use the Milky Way for Navigation

Original image
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

arrow
Animals
Watch a School of Humpback Whales 'Fish' Using Nets Made of Bubbles 

Just like humans, humpback whales catch many fish at once by using nets—but instead of being woven from fibers, their nets are made of bubbles.

Unique to humpbacks, the behavior known as bubble-net feeding was recently captured in a dramatic drone video that was created by GoPro and spotted by Smithsonian. The footage features a school of whales swimming off Maskelyne Island in British Columbia, Canada, in pursuit of food. The whales dive down, and a large circle of bubbles forms on the water's surface. Then, the marine mammals burst into the air, like circus animals jumping through a ring, and appear to swallow their meal.

The video offers a phenomenal aerial view of the feeding whales, but it only captures part of the underwater ritual. It begins with the group's leader, who locates schools of fish and krill and homes in on them. Then, it spirals to the water's surface while expelling air from its blowhole. This action creates the bubble ring, which works like a net to contain the prey.

Another whale emits a loud "trumpeting feeding call," which may stun and frighten the fish into forming tighter schools. Then, the rest of the whales herd the fish upwards and burst forth from the water, their mouths open wide to receive the fruits of their labor.

Watch the intricate—and beautiful—feeding process below:

Original image
iStock
arrow
Big Questions
Why Do Dogs Love to Dig?
Original image
iStock

Dog owners with green thumbs beware: It's likely just a matter of time before Fido turns your azalea bed into a graveyard of forgotten chew toys. When dogs aren't digging up your prized garden, they can be found digging elsewhere in your yard, at the beach, and even between your couch cushions at home. But what exactly is behind your dog's drive to turn every soft surface he or she sees into an excavation site?

According to Dr. Emma Grigg, an animal behaviorist and co-author of The Science Behind a Happy Dog, this behavior is completely normal. "When people say 'why do dogs dig,' the first thing that always comes to mind is 'well, because they're dogs,'" she tells Mental Floss. The instinct first appeared in dogs' wolf ancestors, then it was amplified in certain breeds through artificial selection. That's why dogs that were bred to hunt rodents, like beagles and terriers, are especially compelled to dig in places where such animals might make their homes.

But this tendency isn't limited to just a few specific breeds. No matter their original roles, dogs of all breeds have been known to kick up some dirt on occasion. Beyond predatory urges, Dr. Grigg says there are two main reasons a dog may want to dig. The first is to cool off on a hot day. When stuck on an open lawn with little to no shade, unearthing a fresh layer of dirt untouched by the sun is a quick way to beat the heat.

The second reason is to stash away goodies. Imagine your dog gets bored with chewing his favorite bone but knows he wants to come back for it later. Instead of leaving it out in the open where anyone can snatch it up, he decides to bury it in a secret place where only he'll be able to find it. Whether or not he'll actually go back for it is a different story. "There's a disconnect with modern dogs: They know the burying part but they don't always know to dig it up," Dr. Grigg says.

Because digging is part of a dog's DNA, punishing your pet for doing so isn't super effective. But that doesn't mean you should stand idly by as your yard gets turned inside-out. When faced with this behavior in your own dog, one option is to redirect it. This can mean allowing him to dig in a designated corner of the yard while keeping other parts off-limits, or setting up a raised flowerbed or sandbox especially to satisfy that urge. "You can get him interested in the area by burying a couple bones or some interesting things in there for him to dig," Dr. Grigg says. "I like the idea of buried treasure."

If your dog's motive for digging is more destructive than practical, he may have an energy problem. Dogs require a certain amount of stimulation each day, and when their humans don't provide it for them they find their own ways to occupy themselves. Sometimes it's by chewing up shoes, toppling trash cans, or digging ditches the perfect size for twisting ankles. Fortunately, this is nothing more walks and playtime can't improve.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios