Echo is flying.

Echo could see with his eyes and could hear the many sounds of the forest with his ears. But this was not enough to catch those tiny bugs after the sun went down.

"Mother!" called Echo , "How do you catch those bugs? It is too dark and I can't see them."

"You must use your ears," Mother bat replied. "Ears?" asked Echo, "How can I see with my ears?"

"We use our eyes to passively sense our surroundings," explained Mother Bat," But we have another sense which allows us to actively sense our surroundings."

Echo senses a bug.

"Echo, you can actively call out a high-pitched sound and listen for its echo. The sound will bounce off objects in the forest like trees and tiny insects."

"Using your big ears," she told Echo, "Listen for the sound to return. Depending on how long the sound takes to return and from which direction the sound returns, you can locate objects to avoid, like trees, and objects for food, like tiny insects. This is called echolocation."

Echo tried calling out an ultrasonic chirp. He was amazed at a new world that was not visible to him before. After locating an insect, Echo flew toward it and caught it in his mouth. He then pushed the bug into his mouth with his tail.

"Remember to chew quickly," alerted Mother Bat, "You must begin making your chirps again quickly, so you don't run into a tree."

"This is very hard to do," thought Echo, "This echolocation must take a lot of practice."

"We bats have remarkable senses," Mother Bat continued. "As you get more practice, your chirps will contain different frequencies, or pitches of sound. A very high-pitched sound has a short wavelength that will bounce off of the tiniest of insects, like gnats. Chirps that are not as high-pitched have a longer wavelengths and bounce off larger insects, like beetles."
Bugs flying around. "If you use one chirp that starts low and gets higher, you can not only locate different sized insects, but you can see the the different parts of the insects, like their large bodies and tiny heads."
Echo listened to his mother talk and felt pride in being a bat. All the baby bats and their mothers spent about an hour eating almost their own weight in insects before going back to their home for a rest.
Back 9 Forward