- The audio in this video doesn't include ultrasound (more than 20000Hz), and it's mainly played with audio from 10000 to 15000Hz.
- Depending on your audio environment, the effect may not be expected.

I made this video out of necessity.
The eaves board of my house (Gypsum board on the ceiling of the eaves that protrudes outward from the outer wall of the roof) was peeled off due to the damage of the typhoon.
I left it alone, and recently rats have begun to enter from that hole. So, I was in trouble because I started to hear crunching noises of gnawing a wood.

I investigated the rat repellent sound and tried several smartphone apps and videos, but the following video was the most effective.

Ultrasonic mouse repellent machine (8 hours continuous video)
   • 超音波ネズミ撃退器（8時間連続動画）  

The product in the video is "Rat Repellent Mouse Out" (manufacturer: Sankyo Disinfection), it has a 3-mode selector switches. The frequency bands are 30kHz, 45kHz, and 60kHz, respectively. The effective range is about 200 square meters.
In the original video, 3 modes are edited to constant speed, 0.5x speed, and double speed, so it's a video recording a total of 7 frequencies (2 are overlap): 15, 22.5, 30, 45, 60, 90, 120kHz.
However, the sound of 16kHz or higher is cut in the video uploaded to youtube.


Volume is important. I can expect the effect to be great if I bring the speaker directly into the attic or wall. But in our case, there is no inspection port, so we have to remove the walls and ceiling. I want to avoid it, if possible...
Therefore, I played it at maximum volume from two speakers of the component stereo. That volume : the silent part can be heard as loud static white noise.
The volume was so loud that it could be heard well throughout the house and faintly outside, but it didn't bother the neighborhood.
When I played the original video at a loud volume, the rustling rats sound stopped immediately. But when the rat repellent sound was stopped, the rats returned again, so I played it all night or only during the day.

However, it is repeating a constant tempo, and they got used to that noise. The effect was gradually disappearing.
After all, I have to block the hole.
Therefore, I randomly edited the sound of this original video and mixed it with the sound with a slightly changed pitch, I tried to make more unpleasant sound for the rat.
I playing the edited sound from morning till evening, and after the rats are expelled, I closed the hole of eaves board, case closed.


Notes:
- Be loud volume.
A large amount of stress can be applied to a rat by exposing it to noise of 95 dB or more at a short distance using multiple speakers from various angles. Decibel (dB) is a unit of loudness level: about 60 dB in normal conversation, about 100 dB under guard when a train passes, and about 130 dB for lightning strikes and airplane engine sounds. Stereo sound is 80 to 95 dB, karaoke is 80 dB to 95 dB, and compressor is 80 dB to 95 dB.

- This video doesn't include ultrasound.
The definition of ultrasonic waves is 20kHz or higher, but sounds above 16kHz are cut in both the original and this secondary movie. As long as youtube specifications are so, The audio of all youtube videos is outside the definition of ultrasound. However, I felt the effect, so I think that the sound below 16kHz and ultrasound are the same noise that rats dislike.

- I recommended to watch the reaction of the rats in the original video.
This edited version is an unpleasant sound for humans. So, I recommend that you first try the original video and see the rats reaction for a few days. If you want to get rid of the rats intensively for a short period of time after feeling the effect, or if the rat seems to get used to it in the original video, please use my edited video. Or, I have released a WAV audio file (including ultrasonic waves of 20kHz or higher a little) before posting it on youtube, so I hope that it will be played in a loop. (66MB)
https://drive.google.com/file/d/1S8zF...

Referenced videos and sites (Japanese):
Can rats be repelled by ultrasound? Explain the views of acoustic experts
https://inakasensei.com/mouse-chouonpa

Ultrasonic mouse repellent machine (8 hours continuous video)
   • 超音波ネズミ撃退器（8時間連続動画）  

Bunkaimajin's channel of the original video
   / @bunkaimajin