There are a few reasons why hikers yield to horses. The first reason is that horses are larger and more powerful than hikers. If a horse were to accidentally knock into a hiker, it could seriously injure them. Secondly, horses can be easily startled by loud noises or sudden movements. If a hiker were to startle a horse, it could bolt and run off the trail, possibly injuring itself or the rider. Finally, horses have the right of way on trails. This means that if there is only enough room for one person or animal on the trail, hikers should yield to horses.