The fight-or-flight response (also called the fight, flight, freeze, or fawn response [in PTSD], hyperarousal, or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival
—Rabbits— In rabbits, the physiological and behavioral responses to induced tonic immobility have been found to be indicative of a fear-motivated stress state, confirming that the promotion of TI to increase a bond between rabbits and their owners—thinking the rabbits enjoy it—is misplaced; however, some researchers conclude that inducing TI in rabbits is appropriate for certain procedures as it holds less risk than anesthesia.
—Horses— Over the years the "fight” and "flight” responses in horses have been recognized as a starting point in many training methods. We all have experienced dangerous, or potentially dangerous, situations because of those instincts, and many humans and horses have been hurt because of these responses. The following scenarios are familiar to many of us: • A horse spooks and flees at the sight of flapping plastic. •A tied horse pulls back and fights at the end of the lead. •Upon approaching the trailer, the horse's head goes up and he bolts away from the trailer.
—Cats— An example involving fight is of a cat about to be attacked by a dog. The cat shows accelerated heartbeat, piloerection (hair standing on end, normally for conservation of heat), and pupil dilation, all signs of sympathetic arousal.
—Chameleon— Some species of cold-blooded animals change color swiftly, to camouflage themselves. These responses are triggered by the sympathetic nervous system, but, in order to fit the model of fight or flight, the idea of flight must be broadened to include escaping capture either in a physical or sensory way. Thus, flight can be disappearing to another location or just disappearing in place. And often both fight and flight are combined in a given situation.
—Kara— I don't get scared very easily (unless you make me watch American Horror Story) but usually if I'm in danger I fight back (it's usually just my sister so this isn't a very accurate example) but I know that I would run.