The ultrasonic rat repellent uses the physical rat repellent method, by emitting ultrasonic waves that interfere with the living environment of rats without the need for chemical agents. This method avoids the environmental pollution problems that may be caused by traditional rodent control methods such as rat poison, and does not pose a threat to human health due to chemical residues. For families with children, pregnant women, or pets, this is a very safe choice. As long as it is operated correctly, it will not cause direct harm to family members and pets, and can effectively repel rats.