An animal alerting device system and method for mounting in a vehicle produces a sound that stimulates an alertness response in large animals to reduce the likelihood that the animals will run into a roadway and cause an animal-vehicle crash. The sound produced by the device is a random sound pattern in an audible frequency range. The volume of the sound produced is automatically adjusted for vehicle speed. Different sound patterns may be produced automatically based on different geographical locations of the vehicle in which the device is mounted.