If your horse exhibits "pica", the general term for the consumption of non-nutritive substances, you need to look at both diet and environment for answers.
Behaviour
Horses, like humans, are hard-wired to be social; separation elicits distress. This is normal behaviour – and it is adaptive.
Your horse should display passive body language and easily move out of your way when asked. This article will look at why food-related aggression develops.
The concept of umwelt from the German word meaning “surrounding world,” refers to one’s species-specific perception of reality.