horses are fight or flight animals. Their first instinct will either be to kick or bite in self defense or run away.
A horse has either a flight or fight response. The horse with either run away from what is scaring it, or it will try to fight it.
Horses are prey animals, there instincts are flight and then fight. So they first will flee from the situation and then if that doesnt work they fight.
When a horse is frightened or afraid their first instinct is to Flee, run or get away. known as spooking.
A horse's first instinct if it is afraid is to run.
to bite
Bolt.
To run
flight or fight and if it is afraid it is going to have a flight instinct
They run away or bolt.
Scatter in groups.
run away
Horse will Flee