CATWatch – the only ultrasonic cat deterrent recommended by the RSPB. Cats are usually unwelcome visitors to gardens. Not only do they damage young plants and scare away or kill wild birds, they also leave behind unpleasant deposits! British-made CATWatch is a humane yet very effective deterrent, and the only one of its kind tested and recommended by the RSPB. It works by emitting bursts of ultrasound (inaudible to humans) whenever it detects a cat’s movement or body heat, so cats quickly learn to associate the unpleasant noise with their presence – and leave. CATWatch is portable, easy and quick to set up, and works all year round in all weathers.