“Bunny lines” is a term used to describe the diagonal creases that appear on the upper part of the nose, just beside the eyes. These lines are called bunny lines because they can resemble the creasing of a rabbit’s nose when it twitches or moves.
Bunny lines are often a natural part of facial expression and can become more noticeable when a person smiles, laughs, or scrunches their nose. Like other facial creases, bunny lines are primarily caused by the repeated contraction of facial muscles over time.