# How do swarms of bats use echolocation? **URL:** \ **Category:** Factual Questions\ **Created:** [January 9, 2006, 3:25pm UTC](https://boards.straightdope.com/t/how-do-swarms-of-bats-use-echolocation/339156 "2006-01-09T15:25:16Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 9, 2006, 3:25pm UTC](https://boards.straightdope.com/t/how-do-swarms-of-bats-use-echolocation/339156/1 "2006-01-09T15:25:16Z")
Last night, while watching **Harry Potter and the Temple of Doom** , I noticed a night scene where a cloud of bats swerved around to enter a narrow crevice in the ground. These bats were probably cgi, but don’t real bats do that too? I can see how a flock of birds could gyre and swerve past obstacles using light, by following the nearest wingtips, but how is that accomplished with each bat generating its own sound? Are bat chirps individualized enough so that every bat can pick out its own voice from the cacophony, or is there some sort of hierarchy in which only certain bats [echolocate](http://en.wikipedia.org/wiki/Animal_echolocation) when they’re swarming? Perhaps bats at the _edges_ of a cloud let out a different style of chirp? ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [January 9, 2006, 6:42pm UTC](https://boards.straightdope.com/t/how-do-swarms-of-bats-use-echolocation/339156/2 "2006-01-09T18:42:09Z")
I’m not sure echolocating bats hunt in groups. Whenever I’ve seen large numbers of bats in flight, they’ve never swarmed; they always are traveling in many different directions. It’s kind of looked like the choatic space battle scenes between fighters in the _Return of the Jedi_. My experience with bats is not extensive, however. So take that with a grain of salt. ---
**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\ **Post date:** [January 9, 2006, 6:47pm UTC](https://boards.straightdope.com/t/how-do-swarms-of-bats-use-echolocation/339156/3 "2006-01-09T18:47:03Z")
Echolocation would not only be useful for hunting. A solo bat could use it to navigate around obstacles, as described. However, ‘blind as a bat’ is not an appropriate aphorism - most bats have vision and can see pretty well in dim conditions, IIRC. Thus, they probably navigate by sight in flocks. WAG. You might even have coplex behaviour where a lead bat is using echolocation, (and maybe a few flanking bats at different pitch,) and every other bat in the flock is following their lead, either by sight, or by following their cries sonically. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 10, 2006, 2:10am UTC](https://boards.straightdope.com/t/how-do-swarms-of-bats-use-echolocation/339156/4 "2006-01-10T02:10:53Z")
Bump for the nocturnal posters. [Bat swarm at Carlsbad](http://www.robbukar.com/New_Mexico/pages/page_31.html) These bats may have enough light to see and flock outside the cavern, but how do they manage swarming flight inside, where it’s always dark? ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [June 6, 2009, 1:35pm UTC](https://boards.straightdope.com/t/how-do-swarms-of-bats-use-echolocation/339156/5 "2009-06-06T13:35:45Z")
[Bats ‘recognise other’s voices’](http://news.bbc.co.uk/2/hi/science/nature/8085477.stm) > [@](#): > > A study has revealed how these winged mammals recognise other bats’ voices. > > They are able to differentiate the ultrasonic “echolocation” calls that other bats make as they navigate. > > In the journal PLoS Computational Biology, the scientists report that the bats have an internal “reference” call to which they compare others. > … > “Our analysis showed that each bat has a typical distribution in the frequencies it emits, probably a result of the differences in each animal’s vocal chords.” > > He thinks the bats may have an internal “prototype” - a sort of reference sound against which they can compare these subtle differences. > > This could explain how bats remain in a group when flying at high speeds in darkness, and how they avoid interference between each others’ echolocation calls. The above is good for a _few_ flying bats, but doesn’t yet adress how thousands of them manage to swarm out of a cave. ---
**Author:** ![Oukile](https://avatars.discourse-cdn.com/v4/letter/o/13edae/32.png) [@Oukile](https://boards.straightdope.com/u/Oukile)\ **Post date:** [June 6, 2009, 2:14pm UTC](https://boards.straightdope.com/t/how-do-swarms-of-bats-use-echolocation/339156/6 "2009-06-06T14:14:30Z")
> [@Squink](#): > > [Bats ‘recognise other’s voices’](http://news.bbc.co.uk/2/hi/science/nature/8085477.stm) > The above is good for a _few_ flying bats, but doesn’t yet adress how thousands of them manage to swarm out of a cave. Well, this study is a little limited since it involved a bat distinguishing between the ‘voices’ of two other bats in an otherwise bat-free environment > [@](#): > > So we trained bat A on a platform, playing a sound from bat B on one side and from bat C on the other. He had crawl to where the ‘correct’ sound was coming from. Compared to flying in the middle of a swamp, this does not sounds like very much of a challenging task. Basically, you expect any mammal or bird to do this effortlessly. Nevertheless, one should point out that: - we humans perform pretty well in an equivalent situation, e.g. when we are chatting in a crowded bar. It’s not easy, but we can focus our attention on the voice of our neighbours. With a little bit of extrapolation, we can expect bats to dicriminate their own voice in rather noisy environment, especially since bat must have had quite some selective pressure on their ability to echolocate during their evolution. - the ultrasound emissions as well as bat earing are [directional](http://www.springerlink.com/content/r620351636k06362/): > [@](#): > > When the present data are combined with measurements of the behavioral directionality of hearing at the same frequency (Grinnell and Schnitzler, 1977), the directionality diagram of the entire echolocation system is very narrow and points in the flight direction. This means that bat are not so much disturbed by the emissions of other bats flying in front of them (since these emissions are not directed toward them), nor by the bats behind them (since they don’t hear in this direction).