[Noisebridge-discuss] The rats are getting ballsy

[Tomm]

On 2/26/2010 1:28 AM, Joel Jaeggli wrote:
> Apart from the fact that the reasonably rigorous research on the subject
> says that they don't work, there's also the inverse square law to consider.
>   
Any citations?  From what I've read, continuous sound patterns have been
shown to be ineffectual (see my previous comment about cyborgs), but
discontinuous sound hasn't been shown to be useless.
> and of course:
>
> http://www.ftc.gov/opa/2001/05/fyi0128.shtm
>   

Victor addresses exactly this in
http://www.victorpest.com/advice/all-about/victor-repellents/types-of-repellents

"In the mid 1980s the Federal Trade Commission (FTC) contacted all
manufacturers of electronic pest control products (about 15 at the time)
and required that each provide data for claims being made.  In addition
to repelling rodents, the fraudulent companies claimed repellency of
insects and wild animals.

Most of the 15 companies simply got out of the business as quickly as
they had gotten into it.  Four companies entered into Consent Decrees
that allowed no claims on packaging and put them out of business. 

 The Victor® Ultrasonic PestChaser® prevailed and received the stamp of
compliance.  The claims today are the same ones as were claimed when we
first started with ultrasonic device.  No hype required - the
PestChaser® does exactly as it was invented to do - repels rodents and
keeps them out of your home."

Personally, I think that if there's copious food around, rats will
continue to hang out at Noisebridge regardless of almost anything else
that's done.  Even killing them just delays the time until the next rats
find the space.  If there's no readily available food, no easy way to
get in (or out), and there are noisemakers around (so they can't hear
their kids squeal), I think they'll find someplace else to hang out.

    Tom

> Tomm wrote:
>   
>> I ordered a package of 4 of the Pestchaser ultrasound rodent repellers
>> Rubin mentioned.  My day job is in ultrasound, and I want to take one of
>> the apart and see what they're doing.  They're almost certainly using
>> PZT piezo crystals to achieve the stated 5-7 year battery life, but I
>> want to see what drive circuitry they're using.  I'll install the other
>> 3 at noisebridge - probably won't hurt. 
>>
>> No one will be able to hear these devices at a distance of >50cm or so. 
>> The Pestchaser uses 32khz to 62khz ultrasound, which is far outside
>> human hearing range.  Most people can hear up to about 20khz, some up to
>> about 23khz (myself included), but no one has ears that can directly
>> hear a 32khz sound.  
>>
>> The 40khz air ultrasound devices I work with are barely audible at about
>> 10cm, but mostly because it's so damn loud (115dB) that the 20khz,
>> 10khz, and 5khz harmonics created in the ear are loud enough to be
>> perceived. It's a pulsed device, and sounds like a "tic" when running,
>> not like high-frequency tone.  So, while one might hear a little bit of
>> tic'ing if you put the Pestchaser next to your ear, there's no way
>> you'll near it if it's near the floor and you aren't lying down next to
>> it.  For comparison, a plane taking off from 10m away is 115dB.
>>
>> Even dogs can barely hear 40khz.  See this graph:
>> http://www.lsu.edu/deafness/HearingRange.html  , where their perception
>> of loudness drop about 60dB between a 30khz signal and a 40khz signal. 
>> Humans have a comparable drop between 15khz and 20khz.  40khz is right
>> out.  Mice, on the other hand, hear just fine at 40khz, with the
>> distress call of a young mouse at about 40khz (after all, mice don't
>> want their distress calls to attract the cat, let alone a human!).
>>
>> I've been dubious of the ultrasound devices for pest control.  As anyone
>> in the Cyborg group will tell you, any consistent stimulus will
>> eventually be integrated into your brain, and rodents would just because
>> used to the sound.  The Pestchaser manufacturer claims that it puts out
>> a non-periodic sound and that rodents can't become habituated to it,
>> which I'm skeptical of but I suppose it might work just by annoying
>> them.  After all, rats live in subway tunnels right next to trains
>> rushing by at 130dB+.  The pestchaser says that it sends out a special
>> 46.5khz sound that mimics the sound of a dominant mouse, which sound
>> nifty but likely doesn't help with rats.
>>
>> Speaking of which, I'm pretty sure that ultrasound repellers will work
>> far better with mice than with rats. Mice are at the bottom of the food
>> chain, and anything that moves likely wants to eat them.  A lab
>> researcher friend (that is, um, very much not a vegan) says that it's
>> impossible to get mice to relax  Rats, on the other hand, are smart
>> badasses that chill out all the time, as any rat pet owner will tell
>> you.  Pestchaser claims to have been effective with rats, but I'd guess
>> their "15 of 17 sites cleared" claim were mostly mice sites, with
>> perhaps a few rats deciding that there are easier targets without all
>> this racket.
>>
>> That all said, my experience backs up what I've been told by pest
>> control professionals: plugging holes works the best.  Rats can fit
>> through an opening the size of a quarter, and mice the size of a dime. 
>> Plug them up, and they're less likely to enter not only because of
>> chance (hey look, an open hole!) but because there are a lack of exits
>> (oh shit, nowhere to escape to!)  Spackle won't work because they'll
>> just eat through it.  High density urethane spray foam, available at
>> most any hardware store, is your friend.  I inherited a minor rat
>> infestation at a house in Berkeley, and two cans of spray foam later, I
>> never saw rat traces again.
>>
>>     Tom
>>
>> On 2/24/2010 1:08 PM, Rubin Abdi wrote:
>>     
>>> ====Ultrasonic====
>>> * Get ultrasonic emitters. 
>>> [http://www.amazon.com/Victor%C2%AE-PestChaser%C2%AE-Ultrasonic-Rodent-Repellent/dp/B0015WM4QA/ref=sr_1_4?ie=UTF8&s=home-garden&qid=1267045186&sr=8-4]
>>> * Set them up outside of the space.
>>> ** At the end of the ledge holding the lights in the main stairs.
>>> ** In the not-a-fire-escape stairwell.
>>> ** At the bottom of the stairs under the DJ booth.
>>> * See if any humans can hear them.
>>>
>>> ====Peppermint====
>>> * Get some peppermint.
>>> * Spread it around the space without stinking up the space.
>>>
>>>   
>>>       
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>>     
>