Yesterday there was a webm of a pig being beheaded somewhere on 4chan. Anyways, after the head was severed from the body, the pig first fell and then tried to run. It didn't succeed since men around were holding it.

The thing is how it's possible? The impulse to run should come from the brain, but the pig obviously had been beheaded. It is the same with chickens. I understand that there should be some convulsions and erratic/ chaotic movements in such cases but running is a planned, coordinated movement. So where did the impulse came from? How did the pig's body knew how to run?