reflex
reflex response
reflex action
instinctive reflex
innate reflex
inborn reflex
unconditioned reflex
physiological reaction

But even then, he said, a shot could be the result of a reflex action.

The reflex action when fired upon through a window was to fire back.

They didn't know what to do but there was a quick reflex action from one member of the party.

A: It was just a reflex action, he didn't have a reason.

Then, almost as a reflex action, without thinking, I turned my head toward him and smiled.

I sat up and opened my eyes in one quick reflex action.

Comments on one's size sometimes seem almost as reflex action.

You develop a reflex action of reaching for the bowl.

He didn't expect his orders to do any good; it was only reflex action.

A light came on behind his eyes for the first time, as if up to now he'd merely been operating by reflex action.