Ultrosound +

Ultrasound of different frequencies .
Mosquito from dogs , cats and by other animals , and insects.
NO VIRUSES !
Ultrasound - elastic vibrations in a medium with a frequency beyond the human hearing . Usually ultrasound understand frequencies above 20,000 hertz ..
Although the existence of ultrasound has long been known , its practical use is quite young. In our time, ultrasound is widely used in various physical and technological methods. Thus, according to the speed of sound in the medium is judged on its physical characteristics. Speed ​​measurements at ultrasonic frequencies allows very small error is determined , for example, adiabatic characteristics of fast processes , values ​​of the specific heat of gases , the elastic constants of solids.