It's a study that produced a thousand "long face" puns: Scientists have found that horses have specific facial expressions, and they're very similar to ours.
Researchers from the University of Sussex in the U.K. studied horses' facial muscles and how they move and came up with the Equine Facial Action Coding System, or FACS. They found a wide range of facial expressions, many that are also seen in primates (like us) and dogs and cats. In fact, horses have 17 facial expressions, three more than chimpanzees.
For example, horses raise the inner brow of the eye and widen their eyes in general when they're scared or in generally negative situations, and so do humans. Plus, they tend to "smile" as a submissive gesture. As previous research shows, horses rely on facial expressions to communicate with one another, and they're predominantly visual creatures with strong eyesight.
According to The Guardian, these facial expressions might have evolved to keep family units together, keep away from predators, and move from place to place to find food. Humans may have changed the way horses expressed emotions as we domesticated them through the years.
Though this research shows that horses show emotions through their faces, it's still impossible to know what's going on in their minds. "Horses are undoubtedly emotional animals," author Jennifer Wathan told The Huffington Post. "But what they feel and how that is expressed is a question that we have yet to pin down."
Here's a video from the study, which was published in the journal PLOS One: