(Metro) Dogs may be man’s best friend, but horses have been companion and assistance animals for millenia. In fact, archaeological evidence indicates that humans formed intermingled relationships with horses nearly 5,500 years ago.

Horses provided people with much of the essentials they required for group survival. Khan Academy indicates that the domestication of the horse ushered in an era of innovation in transport and communication. Horses also were invaluable animals on the farm or in early villages.

Horses still serve many practical functions, but they’re more often than not companion animals or relied on for riding hobbies and sport. These 15 interesting facts show just how incredible these beautiful animals are.

Horses can sleep both lying down and standing up.Horses have the largest eyes of any mammal that lives on land.Horses can see colors, but are better at detecting yellows and greens than purples and violets.A horse’s body contains 205 bones.Because a horse’s eye...