Cats sometimes make a funny face after smelling something, leaving mouth slightly open, lips curled and eyes half‑closed. This is called the Flehmen response, a biological reaction where cats use their Jacobson’s organ to analyze pheromones and chemical signals. It’s not disgust but a way of decoding scent messages about territory, reproduction, and emotional states. While normal, if paired with drooling or pain, it may signal dental issues needing veterinary care.