Here's an excerpt from an article written by Ed Dabney, "Bite-Size Trailer Loading."

"For generations horses have been chased, killed and eaten by predators in the wild such as the bear, wolf, lion and yes even the most efficient predator of all, the human. As prey animals their self-preservation instincts have been well honed.

"For the past few hundred years most horses have not been free to roam at will across the open plains. Even though horses have been domesticated for many years, their survival instincts are still very much intact. These powerful instincts are still responsible for much of the horse's natural behavior and decision making process.

"We have confined the horse into the human world of corrals, paddocks, stalls, and trailers. By doing so it now becomes our duty to try to understand the horse's natural instincts and view his life in our world from inside his head, looking through his eyes. In fairness to our horses we must introduce ourselves and our claustrophobic environment to him in a way he can gently understand and gradually learn to accept...."