Why Do Goats Have Such Weird Eyes?

iStock
iStock

Even with their yelling and fainting competing for your attention, it’s hard not to notice a goat’s eyes. Their horizontal, rectangular pupils seem alien compared to the round pupils of people and dogs and the vertical slits of cats. Why do goats’ eyes look like that? And for that matter, why do cats’ eyes look the way they do? In a new study, vision scientist Martin Banks has found that the shape of an animal’s pupils is a clue to its place in the food chain.

Banks and his team looked at the eyes of 214 different species of land animals, and found a clear relationship between the shape of their pupils and their ecological role. Predatory animals that ambush their prey tend to have vertical slit pupils, while herbivores that are prey for other animals usually have horizontal pupils.

The predator-prey divide in pupil shape suggests that the hunters and the hunted gain some advantage from having a specific type of pupil. To find out what those advantages might be, the researchers analyzed the abilities of the two pupil shapes and how they could serve the different visual requirements of predators and prey.

Goats and other grazing animals (like deer, cattle and moose) that are hunted by predators have a pretty simple strategy for not being eaten: look out for danger and run away if they see it. Their eyes need to be able to do two things to support that strategy. “On the one hand, these animals must see panoramically to detect predators that could approach from various directions,” the researchers write. “On the other hand, they must see sufficiently clearly in the forward direction to guide rapid locomotion over potentially rough terrain.”

Horizontal pupils help here, the team found, because their shape creates a sharp panoramic view that’s wider and shorter than what you’d get with a round or vertical pupil and lets the animal see nearly all around itself. A long horizontal pupil also enhances the image quality of objects ahead of and behind the animal, and helps the eye capture more light along the ground and less dazzling overhead light.

Of course, those benefits don’t apply if the pupil stays oriented the same way and becomes vertically aligned when the animal tilts its head to graze. After watching grazing animals at the zoo, though, the researchers found that their eyes rotate to stay horizontally aligned with the ground whether their heads are upright or face down in the grass.

For a land animal that’s in danger of being eaten by something else and has few options besides being aware of its surroundings and running away, the researchers say that a long horizontal pupil seems to be ideal. In other words, goats have weird eyes because they help keep goats alive.

Meanwhile, the team found that vertical, slit-shaped pupils help small ambush predators like cats and snakes judge the distance of prey and other objects so they know how far they have to pounce.

Plano, Texas Is Home to a Dog-Friendly Movie Theater That Serves Bottomless Wine or Whiskey

K9 Cinemas
K9 Cinemas

For dog owners in Plano, Texas, movie night with Fido no longer just means cuddling on the couch and browsing Netflix. The recently opened K9 Cinemas invites moviegoers—both human and canine—to watch classic films on the big screen. And the best part for the human members of this couple? Your $15 ticket includes bottomless wine or whiskey (or soft drinks if you're under 21).

The theater operates as a pop-up (or perhaps pup-up?) in a private event space near Custer Road and 15th Street in Plano. Snacks—both the pet and people kind—are available for $2 apiece. Dogs are limited to two per person, and just 25 human seats are sold per showing to leave room for the furry guests.

Pet owners are asked follow a few rules in order to take advantage of what the theater has to offer. Dogs must be up-to-date on all their shots, and owners can submit veterinary records online or bring a hard copy to the theater to verify their pooch's health status. Once inside, owners are responsible for taking their dog out for potty breaks and cleaning up after any accidents that happen (thankfully the floors are concrete and easy to wipe down).

While many of the movies shown are canine-themed—a recent screening of A Dog's Journey included branded bandanas with every ticket purchase—they also hold special events, like a Game of Thrones finale watch party (no word on how the puppers in attendance responded to Jon Snow finally acknowledging what a good boy Ghost is).

13 Fascinating Facts About Bees

iStock.com/florintt
iStock.com/florintt

Sure, you know that bees pollinate our crops and give us honey. But there's so much more to these buzzing insects than that.

1. Bee stings have some benefits.

A toxin in bee venom called melittin may prevent HIV. Melittin can kill HIV by poking holes into the virus's protective envelope. (Meanwhile, when melittin hitches a ride on certain nanoparticles, it will just bounce off normal cells and leave them unharmed.) Scientists at Washington University in St. Louis hope the toxin can be used in preventative gels.

Bee stings may also ease pain caused by rheumatoid arthritis. Researchers at the University of Sao Paulo found that molecules in bee venom increase your body's level of glucocorticoid, an anti-inflammatory hormone.

2. Bees work harder than you do.

During chillier seasons, worker bees can live for nine months. But in the summer, they rarely last longer than six weeks—they literally work themselves to death.

3. When bees change jobs, they change their brain chemistry.

bees flying to a hive
iStock/bo1982

Bees are hardwired to do certain jobs. Scout bees, which search for new sources of food, are wired for adventure. Soldier bees, discovered in 2012, work as security guards their whole life. One percent of all middle-aged bees become undertakers—a genetic brain pattern compels them to remove dead bees from the hive. But most amazingly, regular honeybees—which perform multiple jobs in their lifetime—will change their brain chemistry before taking up a new gig.

4. Their brains defy time.

When aging bees do jobs usually reserved for younger members, their brain stops aging. In fact, their brain ages in reverse. (Imagine if riding a tricycle didn't just make you feel young—it actually made your brain tick like a younger person's.) Scientists at Arizona State University believe the discovery can help us slow the onset of dementia.

5. Bees are changing medicine.

To reinforce their hives, bees use a resin from poplar and evergreen trees called propolis. It's basically beehive glue. Although bees use it as caulk, humans use it to fight off bacteria, viruses, and fungi. Research shows that propolis taken from a beehive may relieve cold sores, canker sores, herpes, sore throat, cavities, and even eczema.

6. Bees can recognize human faces.

Honeybees make out faces the same way we do. They take parts—like eyebrows, lips, and ears—and cobble them together to make out the whole face. It’s called "configural processing," and it might help computer scientists improve face recognition technology, The New York Times reports.

7. Bees have personalities

Even in beehives, there are workers and shirkers. Researchers at the University of Illinois found that not all bees are interchangeable drones. Some bees are thrill-seekers. Others are a bit more timid. A 2011 study even found that agitated honeybees can be pessimistic, showing that, to some extent, bees might have feelings.

8. They get buzzed from caffeine and cocaine.

bumblebee on a flower
iStock/Whiteway

Nature didn't intend for caffeine to be relegated to your morning pot of coffee. It's actually a plant defense chemical that shoos harmful insects away and lures pollinators in. Scientists at Newcastle University found that nectar laced with caffeine helps bees remember where the flower is, increasing the chances of a return visit.

While caffeine makes bees work better, cocaine turns them into big fat liars. Bees "dance" to communicate—a way of giving fellow bees directions to good food. But high honeybees exaggerate their moves and overemphasize the food's quality. They even exhibit withdrawal symptoms, helping scientists understand the nuances of addiction.

9. Bees have Viking-like navigation techniques.

Bees use the Sun as a compass. But when it's cloudy, there's a backup—they navigate by polarized light, using special photoreceptors to find the Sun's place in the sky. The Vikings may have used a similar system: On sunny days, they navigated with sundials, but on cloudy days, sunstones—chunks of calcite that act like a Polaroid filter—helped them stay on course.

10. Bees can solve hairy mathematical problems.

Pretend it's the weekend, and it's time to do errands. You have to visit six stores and they're all at six separate locations. What's the shortest distance you can travel while visiting all six? Mathematicians call this the "traveling salesman problem," and it can even stump some computers. But for bumblebees, it's a snap. Researchers at Royal Holloway University in London found that bumblebees fly the shortest route possible between flowers. So far, they're the only animals known to solve the problem.

11. Bees are nature's most economical builders.

In 36 BCE, Marcus Terentius Varro argued that honeycombs were the most practical structures around. Centuries later, Greek mathematician Pappus solidified the "honeycomb conjecture" by making the same claim. Almost 2000 years later, American mathematician Thomas Hales wrote a mathematical proof showing that, of all the possible structures, honeycombs use the least amount of wax. And not only are honeycombs the most efficient structures in nature—the walls meet at a precise 120-degree angle, a perfect hexagon.

12. Bees can help us catch serial killers.

Serial killers behave like bees. They commit their crimes close to home, but far enough away that the neighbors don't get suspicious. Similarly, bees collect pollen near their hive, but far enough that predators can't find the hive. To understand how this "buffer zone" works, scientists studied bee behavior and wrote up a few algorithms. Their findings improved computer models police use to find felons.

13. Bees are job creators.

beekeeper working with bees
iStock/Milan_Jovic

The average American consumes roughly 1.51 pounds of honey each year. On top of that, the U.S. Department of Agriculture estimates that honeybees pollinate up to 80 percent of the country's insect crops—meaning bees pollinate over $15 billion worth of crops each year.

This article was updated and republished in 2019.

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