When it comes to communicating with humans, Mr. Ed taught us that horses speak shockingly good English. But to each other? Researchers at the University of Sussex have determined that when it comes to intra-species communications, horses put a lot of stock in the direction and placement of their ears.

“Previous work investigating communication of attention has focused on cues that humans use – body orientation, head orientation and eye gaze. But no one had gone beyond that. We found that in horses, their ear position was also a crucial visual signal. In fact, horses needed to see the detailed facial features of both eyes and ears before they would use another horse’s head direction to guide their choice,” said researcher Jennifer Wathan.

The study involved buckets of food and pictures of horses. They lead each horse to a point where there were two buckets of food, with an image of a horse on the wall behind them. Horses would use cues from the ears and eyes in the image to direct their choice of bucket, but the choices became random when the ears and eyes were obscured in the image.

Wathan notes that while it’s taken science a while to confirm the hypothesis, anyone who’s worked with horses or other animals with “mobile” ears has long known the role they play in communication. Catd and dogs, for instance, communicate interest, fear and anger very clearly based on how they move their ears.

“This study emphasises that animals other than primates are aware of subtle differences in facial expression and can use these to guide the decisions that they make. Fine scaled facial movements can indicate important changes in attention and emotional state and are likely to be crucial in determining social behaviour in a wide range of animals,” said Professor Karen McComb, a coauthor of the paper.