An Ohio State University study found that horses can identify wolves from video footage alone, with no sound or smell cues — their heart rates spiked physiologically even though they showed no visible fear response. This demonstrates surprisingly sophisticated threat detection in prey animals, suggesting they can assess danger through visual predator recognition without prior experience or multisensory confirmation. The research adds nuance to how animals balance threat awareness with survival strategy — hiding fear may prevent predators from targeting animals that appear weak or panicked.