Abstract: This disclosure concerns an invention used to deter auto collisions with animals, and more specifically to allow standard automobile horn to be altered in a manner such that the noise alerts animals, particularly deer, to the presence of an approaching vehicle. A timer/oscillator is selectively connectable between the vehicle horn actuator (e.g., the button on the steering wheel of the vehicle) and the vehicle horn. When the timer is connected between the horn actuator and the horn, a continuous input to the horn actuator is converted to an intermittent horn output (preferably cycling between 2-20 Hz), this intermittent horn output being synchronized with the timer pulses. Such cycling of the horn causes a flight response in animals when sounded in their vicinity.