1
00:00:00,000 --> 00:00:03,000
You do look like you're looking for something.

2
00:00:03,000 --> 00:00:05,000
My name is Mrs. Chris Lewis. Can I help you?

3
00:00:05,000 --> 00:00:08,000
Hi, I'm Matthew, and this is Catherine, and we're working on a problem.

4
00:00:08,000 --> 00:00:13,000
It's a sound problem, and we really need to learn more about how high frequency travels.

5
00:00:13,000 --> 00:00:18,000
I may be able to help you. Let me show you something that uses high frequency sound.

6
00:00:18,000 --> 00:00:21,000
Let me introduce you to a big brown bat.

7
00:00:21,000 --> 00:00:23,000
Wow! Does he bite?

8
00:00:23,000 --> 00:00:26,000
No, you can touch him gently if you'd like.

9
00:00:26,000 --> 00:00:28,000
Do bats use high frequency sounds?

10
00:00:28,000 --> 00:00:30,000
Sure. Bats hunt in the dark.

11
00:00:30,000 --> 00:00:35,000
They use high frequency sounds and listen for the echoes in order to navigate and find food.

12
00:00:35,000 --> 00:00:39,000
That's great. We heard that high frequency sounds don't travel very far.

13
00:00:39,000 --> 00:00:41,000
Is that true for bats?

14
00:00:41,000 --> 00:00:45,000
Yes, that's true. Air absorbs sound, especially high frequency sound.

15
00:00:45,000 --> 00:00:51,000
Some bats can hear things 60 feet away, but the average is only about 15 feet away.

16
00:00:51,000 --> 00:00:55,000
In school, we just did an experiment on how fast sound travels.

17
00:00:55,000 --> 00:00:58,000
This sounds amazing, but does it really help the bats?

18
00:00:58,000 --> 00:01:02,000
Oh, yes, it does. A bat can tell the speed and direction of a moving object,

19
00:01:02,000 --> 00:01:05,000
whether it's alive or not, even if it's hard or soft.

20
00:01:05,000 --> 00:01:08,000
In fact, in a perfectly dark room very much like this,

21
00:01:08,000 --> 00:01:14,000
a bat can fly through without running into a moving wire that's as thin as a human hair.

22
00:01:14,000 --> 00:01:19,000
In fact, a big brown bat can catch up to 600 mosquitoes in one hour.

23
00:01:19,000 --> 00:01:21,000
600 mosquitoes an hour?

24
00:01:21,000 --> 00:01:22,000
Doesn't that seem incredible?

25
00:01:22,000 --> 00:01:23,000
Yeah.

26
00:01:23,000 --> 00:01:25,000
Thanks, Mrs. Lewis. That was so fun.

27
00:01:25,000 --> 00:01:26,000
Thanks.

28
00:01:26,000 --> 00:01:27,000
Bye. Good luck.

29
00:01:27,000 --> 00:01:28,000
Bye.