The Cat Stop motion detector is a very good way to train cats to keep away from certain areas (like bird feeders and birdbaths). It emits a high pitched, ultrasonic noise that drives cats away but does not bother humans. Simply place the Cat Stop® facing the area you want to be cat free. The built in motion sensor detects the animal entering the area and emits a piercing, high decibel alarm. It startles the cat and frightens it away. Since the sound is ultrasonic; you and your neighbors cannot hear it. It is most effective on small animals(under 20 pounds) with passive personalities.
Cat stop ultrasonic repellent
Protects about 330 square feet
No controls or adjustments
Install battery and position in your garden
Humane and effective