Stay close please children. In this lesson, we’re going to learn about how different animals communicate using sound, and not just any sound, ultrasound. Sounds are made up of invisible waves ...

But mimicking the sounds of animals isn't as easy as woofing or purring. [Marko purring] Though he can do that, too. Picking the right sounds involves carefully examining both objects and surfaces.

Ultrasonic sounds are high-frequency sound waves that exceed 20,000 hertz, a range far beyond what the human ear can detect.