My car came factory equipped with NUCAWS, or the Nocturnal Ungulate Collision Avoidance Warning System. It consist of these electromagnetic transducers which cause the air molecules to vibrate very quickly. If the intensity setting on NUCAWS is high enough, the deer will detect the vibrations and at least become more cautious, if not avoid the area. There is a backup NUCAWS also installed which is effective once you actually see a deer Activating the secondary NUCAWS will often break the "deer in the headlights" trance long enough for them to exit the roadway. Secondary NUCAWS is usually activated with a button somewhere on the steering column. Primary NUCAWS, being a background system - is usually installed on the dashboard between the driver and passenger seats. Since Primary NUCAWS is also detectable by humans, you should avoid using the system at extremely high intensity levels when driving through residential neighborhoods late at night.