Studies have proven that rat becomes immune with only one kind of ultrasound. Also rat becomes ultrasound deaf or in another words ultrasound does not affect them. It is important to have sound with random frequency. It should be able to confuse the rats and rodents with different type of sound.
A particular type of sound can threaten the rat with confuse. There should be perfect frequency along with amplitude and reorientation power of the sonic or ultra sound. The rats immediately stops eating food because of fear. And rat – rodent try to leave the place at they feel sick in the unsafe atmosphere. Ultrasound is most effective way to drive rats out.
Principle of ultrasound to drive away rats
The principle of ultrasound is from the natural phenomenon of earthquake. Earthquake generates ultrasound. Rats can listen the threatening sound as they got the listening capacity of more then 60 KHz. And they run away or leave the place immediately. Similar principal is used for rat eliminator device. But if the device is emitting a constant frequency the rat will become immune and they may start enjoying the ultrasound, suggest rat studies. So the ultrasound can become entertainment for them! And the repellent will become attraction point.
Rat behavior and ultrasonic studies have shown that if a powerful ultrasound with modulated frequencies and randomly variable sound is generated at high amplitude it gives good results for rat control. And it also avoids the immunity factors of rat or rodent.