Patent ID: 7719430

Claim:
An apparatus for the virtual fencing of an animal, said apparatus comprising: a microprocessor configured to continuously determine the position of an animal relative to a target and to determine whether the animal is moving relative to the target; and a stimulus unit for applying a sensory stimulus to the animal in response to signals received from the microprocessor; wherein the microprocessor configuration is programmed such that if the distance between the animal and the target is less than a predetermined distance and, if the animal is moving in a direction towards the target, a stimulus is applied to the animal and the microprocessor configuration is further programmed to: withdraw the stimulus when the animal stops while the distance between the animal and the target is less than the predetermined distance; withdraw the stimulus when the animal retreats from the target while the distance between the animal and the target is less than the predetermined distance; and withdraw the stimulus when the animal accelerates while the distance between the animal and the target is less than the predetermined distance.