Sometimes an unknown situation comes up, or a threat is perceived and fear will induce the need for the horse to protect themselves. How do they do this?
Horses are known to be flight animals. In most cases, when a horse feels threatened, they would rather flee than fight.
The domestic horse has very limited options for flight so fight can easily become one of it’s primary defense mechanisms related to fear or self-protection.
As mentioned, chasing is another behavior you may see when a horse is protecting itself. Often a horse will chase the perceived threat with his head low to the ground, ears back, and sometimes even showing teeth.
Horses can also kick out at anything that is annoying them. Whether you classify this as “protecting themselves” or just being obstinate, they are attempting to remove the annoyance from their proximity.