A swift deer standing paralyzed in front of a running vehicle, instead of walking away! It’s a sight to behold, Isn’t it?
When a deer sees the lights of an approaching vehicle, instead of running away, it remains frozen. The lights of the vehicle scare the animal so much that it stands paralyzed.
Deer have fantastic night vision, thanks to the presence of a high number of rod cells in their eyes, which helps them to see clearly at night unlike humans. However, when a car’s headlight beam falls into their eyes, the deer becomes blinded by the bright light and it just stands still to wait for its eyes to adjust to that brightness, which makes it look like the deer is transfixed to the spot.
But the expression ‘deer in the headlights’ is used informally in American English to suggest someone caught in a state of paralyzing surprise, fear, or bewilderment.
~ When he accused me of stealing, instead of shouting at him, I just stood there like a deer in the headlights ~