Does your otherwise steady horse get nervous on dense, narrow trails? Not to worry—his behavior is completely normal. Here’s why:
Your horse uses each of his eyes separately to see the world around him. Your eyes, set in the middle of your face, give you a natural ability to focus on a narrow trail ahead of you and keep peripheral distractions to a minimum. But because your horse is a prey animal, his eyes are set on the side of his head, giving him relatively poor straight-ahead vision but excellent wide-field vision, which is necessary for spotting predators. Except for two small blind spots, one right in front of his nose and another directly behind his tail, your horse can nearly see 360 degrees around his body. That’s why he notices objects or movements behind him that you can’t even see without turning around. Being able to see all around his body helps the horse spot predators lurking in the wild.
Dense woods eliminate your horse’s wide field of vision and complicate matters with changing patterns of dappled light. Horses have poor depth perception as it is. It is hard for a horse to tell how far away an object is from him or how deep an object is, particularly when it is close to him. That’s why horses will often bob their heads up and down when they’re looking at objects that are up close and down low to them—they’re trying to get a grasp of them. With limited sight on a dense, narrow trail, it’s common for horses to feel nervous about what might be coming out of the woods, which increases their spookiness. It can also make horses extra defensive and they may kick out at horses that approach them from the side or behind.