--- title: Echolocation: how bats see with sound — a lesson of Mova's school · trees and pragmatics description: «Echolocation: how bats see with sound», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Shout «hello» in a big empty hall and a moment later the walls shout it back: that returning sound is an echo. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / Echolocation: how bats see with sound # Echolocation: how bats see with sound Lesson 229 of the biology course of Mova's primary school: 17 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/229-echolocation-how-bats-see-with-sound/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/0/) — Shout «hello» in a big empty hall and a moment later the walls shout it back: that returning sound is an echo. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/1/) — A hunting bat does the same trick hundreds of times a second, with squeaks far too high for us to hear, and listens to the echoes. - [2](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/2/) — From the echo the bat's brain works out how far away a moth is, which way it is flying and even how big it is, so it «sees» with its ears. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/3/) — Watch bats round a streetlamp at dusk: they dart after gnats in the dark and never bump into each other, all thanks to echoes. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/4/) — Using echoes to find things is called echolocation, and bats had it for millions of years before people invented machines that do the same. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/5/) — Bats catch moths and gnats in the dark by shouting very high squeaks and listening for the echoes. - [6](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/6/) — Most bat calls are ultrasound, too high for grown-ups to hear; a bat detector turns them into clicks we can hear. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/7/) — No bat is blind: small bats see quite well in dim light, and big fruit bats called flying foxes find fruit by sight and smell and mostly do not echolocate. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/8/) — Just before it grabs a moth, a bat calls faster and faster, up to about 200 calls a second; this is called the feeding buzz. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/9/) — Some tiger moths click back at bats to jam their echoes or warn that they taste nasty, and some moths can hear bats and dive away; the fluffy scales on some moths' wings soak up sound, so the bat hears less echo. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/10/) — Bats rest upside down, gripping with their toes, so they can drop straight into flight, because taking off from the ground is hard for them; a lock in the toe tendons holds them without effort. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/11/) — Bracken Cave in Texas holds about 15 million bats in summer, and each mother finds her own pup by its call and smell; when they all fly out at dusk, the huge cloud of bats shows up on weather radar like a rain cloud. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/12/) — Real vampire bats are tiny, live in Central and South America and mostly lap blood from sleeping cows, horses and birds; they share food with hungry friends. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/13/) — Bats are the only mammals that can truly fly, and about one in five kinds of mammal is a bat. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/14/) — In the 1790s Lazzaro Spallanzani found that bats with covered eyes still dodged threads but bats with blocked ears crashed; only in 1938 did special microphones prove bats use ultrasound. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/15/) — A small bat can catch hundreds of midges in an hour, so bats are free pest control. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/229-echolocation-how-bats-see-with-sound/16/) — Bat boxes give bats safe places to sleep as old hollow trees and barns disappear, and in Britain bats and their roosts are protected by law. - ← previous: [Cartoon pets and animal myths put right](https://md.mova.elamur.ai/free/en/corpora/school/biology/228-cartoon-pets-and-animal-myths-put-right/) - next →: [Echolocation in the sea and in people: dolphins, whales, swiftlets and clicking humans](https://md.mova.elamur.ai/free/en/corpora/school/biology/230-echolocation-in-the-sea-and-in-people-dolphins-whales-swiftlets-and-clicking-humans/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)