[Noisebridge-discuss] The rats are getting ballsy

[Tomm]

Just a word of warning - urethane spray foam is so effective at sealing
holes that even a dab will _never_ come off of porous clothing.  Like,
four years later, there's still a crunchy spot on a pair of my work
jeans.  It's so sticky it can't be wiped off when wet, and all I could
do is file down the excess after it dried.  Caveat emptor (literally
speaking).

    Tom

On 2/25/2010 6:43 PM, Kelly wrote:
> You know it's funny, but I've been craving spray foam for weeks (see,
> Ben? I knew it would be useful). Totally unrelated to the rat problem.
> Just, yknow, we've been doing construction and working with all sorts
> of lovely substances light sealing the darkroom and I just keep
> thinking, "Isn't there some way we require spray foam? I should
> probably get som, right? Just in case?" Cause man that stuff is
> awesome. And satisfying.  I mean, maybe it's my OCD.  But it's just so
> _thorough_.
>
> So what I'm saying is that I'll buy some spray foam (can't afford
> much) and I'll gladly deploy as much spray foam as NB can provide.
>
> -K
>
> On Thu, Feb 25, 2010 at 15:18, Tomm <tomm.fire at gmail.com> 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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>>     
>