This is very easy and good instructable for those who are in trouble for pests.This device will work on any pests those who can sense ultra sonic sound.Basically those who are willing to make any small firm like sunflower,paddy,vegetables,flower ,this is absolutely good for them.In this device we use frequency range for the pests who cant tolerate the ultrasonic sound.

## Step 1: Parts List

1.NE555 Timer IC

2.Capacitor (0.1uF,0.001uf)

3.Resistor (R1=150 ohm,R2=100 ohm)

4.buzzer

5.Veroboard

6.Soldering Iron

## Step 2: Circuit Diagram

In this instructables we use the NE555 IC that can generate both pulse and frequency.This ic is also cost effective.To build this circuit follow the circuit diagram with the specific value.In top i use 150 ohm and 100 ohm and 0.1uF capacitor that can generate 42 khz frequency that can repell the mosquito.But u can also use different value for different pests.

## Step 3: Different Frequency for Different Pests

Here some of the frequency range,in which pest can be repelled.Follow this frequency range and replace your resistance and capacitance value.

## Step 4: Calculation

Suppose we want to repel mosquito then we can take this values.

R1=150

R2=100

C=0.1 uF

The formula for 555 astable mode frequency:

f=1.44/(R1+2R2)*C

=1.44(150+200)*0.01*10^-6

=42Khz

you can change the frequency with this formula.

## Step 5: Conclusion

U have to use a 0.01uF capacitor in pin no 5 of 555 timer.

Use 5-15 v to operate the device.Hopefully this will work good in your desired frequency.

Go on !!!

Its not working for me could you help me.I am able to hear it's 'teeeeeeeeeeeeeee' sound.will it work on ants?
<p>Maybe you used a normal piezo element try it with a simple 8ohm speaker or a piezo beeper without an exciter circuit.</p>
<p>Very Interesting!! Only I hoped it would also help with insects!, thanks for sharing.</p>
<p>In fact insects don't care for sounds. The exception is mosquito for a certain reason. The buzz sounds like a male flight and repels female already pregnant, those who are the most dangerous for us, that's it. </p>
<p>just saw it now, thanks</p>
<p>the frequencies at the chart you uploaded are the hearing range for different animals-not the repeling frequencies..</p>
<p>you can use this range. :)</p>
<p>ami kintu ekta banaiese oitaie kintu variable register use korsi....btw nice post dost..:D :) </p>
<p>lol...how it works?</p>
<p>sabash</p>
<p>Interesting idea. Thank you for sharing the details.</p><p>Have you tested this to actually scare off any pests?</p>
<p>Yes..you can apply the formula and build a circuit of your own.Then u can test it to repell any pest.Btw set the exect value to get the proper frequency.Hopefully it will work.</p>
as far as i know, for the mosquitos is a myth http://www.bbc.com/news/magazine-20669080
<p>Interesting concept. I believe your chart under Step 3 is the range of frequencies that the listed species can hear. That's why humans are included.</p><p>The US Federal Trade Commission issued a notice that many similar devices are not very effective, if at all: <a href="https://www.ftc.gov/news-events/press-releases/2001/05/ftc-warns-manufacturers-and-retailers-ultrasonic-pest-control"> https://www.ftc.gov/news-events/press-releases/20...</a></p>
<p>I see humans are listed as pests too in your chart, I cannot dispute but that some are. ☺</p>