Abstract: A device for modifying the undesirable behavior of animals is disclosed which utilizes integrated circuitry to achieve a small size and light weight. Discrimination circuitry analyzes audible indications of undesirable animal behavior. Upon detection of undesirable behavior, sound generation circuitry produces a pattern of high-intensity sounds known to cause aversive behavior in animals. The staccato pattern varied, so that animal habituation to the sounds is avoided. Circuitry is provided for increasing or decreasing the effective intensity of the sounds according to the behavior of the animal over a previous time interval.