12 Astonishing Facts About Horses

Horses have existed for 55 million years. Our own human history has been greatly shaped by our partnership with these creatures, and they have been shaped by us as well. Since domesticating the horse 6,000 years ago, humans have created hundreds of horse breeds, used for everything from racing and war to plowing and pulling carts and carriages.

In honor of these widely adored animals, here are 12 fascinating facts you never knew about them.

1. Horses Have a Wide Range of Vision

Horses' eyes are located on the sides of their heads, so they have a wide range of vision. They can see nearly 360 degrees and have blind spots only immediately in front of and behind their bodies.

Horses mostly use monocular vision, meaning the eyes are used separately. That means a horse can see and process different things happening on different sides of its body. When a horse switches to binocular vision, it's to focus both eyes on a single object in front of it.

2. They Cannot Vomit

Horses are physically incapable of vomiting. There are a number of anatomical reasons for this, such as the strength of the muscles in the esophagus, the specific way the esophagus connects to the horse's stomach, and the location of the stomach itself.

The evolutionary reason for this isn't known for sure, but one theory is that it is protective. The back-and-forth motion of a full gallop could theoretically induce vomiting that would allow a predator to catch it, so evolution may have eliminated the concern entirely.

3. They Are Related to the Rhinoceros

Horses are members of the genus Equus, which is considered the only extant group in the horse family. The genus includes not only the domesticated horse (Equus caballus) but also the Przewalski's horse, zebras, and asses such as donkeys. Surprisingly, though, these are not the horse's closest living relatives.

As an odd-toed ungulate, the horse is closest related to the similarly hooved rhinoceros.

4. Arabian Horses Have a Unique Build

Arabian horses stand out for their historical importance, particularly to the culture and lives of desert tribes in the Middle East. But they are also distinct from other horse breeds because of their unique build.

Arabians have a greater bone density than other horses, and they also have a shorter back with one fewer lumbar vertebrae. Additionally, Arabians have one fewer pair of ribs, and their ribs are set wider apart. While they are known for carrying their tails high like a flag behind them, that may have less to do with high spirits and more to do with having two fewer tail vertebrae than other horse breeds.

5. Ponies and Miniature Horses Are Different

All miniature horses are ponies, but not all ponies are miniature horses. Any horse that is shorter than 14.2 hands (58 inches) at the withers qualifies as a pony. According to the American Miniature Horse Association, miniature horses must be no taller than 34 inches, which puts them squarely in the pony category in addition to being their own group.

However, many enthusiasts consider miniature ponies to be a distinct breed of horse because they maintain standard horse body proportions, unlike ponies that have shorter legs, longer bodies, and an overall stockier build.

6. Their Teeth Contain Lots of Information

Much can be learned about a horse through its teeth, starting with its gender. Male and female horses have a different number of teeth; males have 44 while females have between 36 and 44.

You can also estimate a horse's age by looking at its teeth. According to the University of Missouri, this can be done by observing the occurrence of permanent teeth, the disappearance of cups (indents in each tooth), the shape of the surface of the teeth, and the angle at which the top and bottom rows meet.

7. There Is Only One Truly Wild Horse Species

There is only one subspecies of horse that is truly wild, not just feral: Przewalski's horse. Although it was once found throughout Europe and Asia, the species is now limited to just Mongolia, China, and Kazakhstan. They differ from domestic horses in their large heads, thick necks, short legs, and overall stocky builds.

You're probably wondering about the "wild" populations that roam in the western U.S. and famously on the beaches of North Carolina's Outer Banks. These mustangs share a species designation with domesticated horses and, actually, derived from domesticated populations. That said, these horses are considered feral, not wild.

8. They Have Muscular Ears

Horses' ears may be small, but they are mighty. Each ear contains 10 muscles (compared to humans' three) and can move 180 degrees, from facing directly forward to directly backward. They can also distinguish and identify distinct sounds by directing their hearing to specific areas.

Horses use their muscular ears to communicate, such as by pinning them back to indicate anger or for guidance. In one study, horses were found to make decisions based on where another's ears were pointing, telling us that the animals may use their ears to direct each other.

9. Their Funny Faces Don't Indicate Laughter

When a horse curls its upper lip and raises its head in the air, many people see it as a funny face or an expression of laughter. That's inaccurate.

Rather, this behavior is called the flehmen response, and it's about getting a better whiff of an interesting smell. The action allows pheromones and other scents to transfer to the vomeronasal organ (VMO), which then sends signals to the brain that can trigger physiologic and behavioral reactions.

Stallions show the flehmen response most often as they pick up the pheromones of mares. Mares will flehmen shortly after birth as a response to the pheromones of their newly born foal.

10. One Breed Has a Metallic Coat

The Akhal-Teke horse is famous for its coat. While many well-tended horses have beautiful sheens, this breed boasts a naturally metallic shine.

It all has to do with the structure of its hair. In most horse breeds, hair strands have an opaque core, but for the Akhal-Teke, that core is extremely small or completely absent. The transparent part of the hair takes its place, bending and refracting light as it passes through and giving each hair an apparent shimmer.

11. They Are Highly Intelligent

Horses are smart creatures, and there are studies to prove it.

Research published in 2012 found that horses use input from several senses to identify—and remember—people. The horses were able to distinguish between a familiar and unfamiliar human by their voices alone (without using sight or smell). The horses could also do the opposite, telling the difference using just the sight and smell of the people, not hearing their voices.

Meanwhile, the Equine Research Foundation has disproven an assumption about horses that they cannot transfer information between different sides of the brain. Its study found that horses were easily able to employ this skill of interocular transfer, recognizing objects with one eye that they had learned about with the other.

12. Many Are in Trouble

Przewalski's horse is listed by the IUCN Red List as an endangered species with only 178 mature individuals remaining. However, populations have been increasing thanks to worldwide efforts to bring the only modern-day wild horse back from the brink of extinction. Just one example is the Foundation for the Preservation and Protection the Przewalski Horse, established in the Netherlands. The organization worked for almost 40 years on breeding strategies and ultimately released more than 350 horses in Hustai National Park in Mongolia.

In the U.S., the feral mustang is also believed to be edging closer to extinction, but because it's technically a domesticated breed, it can't be listed on the Endangered Species List. The IUCN has not assessed it.