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How Cities Are Using Dry Ice To Kill Rats (usatoday.com)
Some of the United States' biggest cities have resorted to using dry ice to kill rats. Since dry ice (frozen carbon dioxide) turns into a gas, sanitation officials simply need to drop chunks of it into rat infested burrows and let science do the rest. Longtime Slashdot reader mi writes: USA Today reports: "Earlier this week, USA TODAY observed Chicago sanitation department workers at one of the city's oldest parks scoop chunks of smoking dry ice into a burrow before quickly covering the entry and exit holes with dirt and newspaper to stop any rats from escaping as the -109.3-degree Fahrenheit gas dissipated. Sanitation workers say they treat burrows during morning hours, when rats are less active and most likely to be huddled inside the burrows. The asphyxiated dead rats then decompose in place and out-of-sight of city denizens who count the disease-carrying vermin among the vilest of indignities of urban living. 'We are seeing 60% fewer burrows in areas where we are using the dry ice,' said Charles Williams, Chicago's streets and sanitation commissioner. 'It's more environmentally friendly, and it's very humane on the rodents as well.'" Humane or not, what is so especially "undignified" about rats? What makes them worse, than, for example, cats, deer or wild horses?
who fuckin cares. They're rats.
Well they tried C4 and the neighbors bitched about the noise. you just can't make anyone happy these days.
They carry disease, eat infrastructure, chew holes in your house, shit and pee on your stuff, chew holes in your stuff, eat and contaminate your food, and many more things I can't fit into the margin of this book.
The normal way is to make them eat a lot of warfarin until internal bleeding kills them.
If you want to kill stuff than is not neatly lined up in the stockyards it's generally going to be messy and horrible.
"Humane or not, what is so especially "undignified" about rats? What makes them worse, than, for example, cats, deer or wild horses?"
The author of the summary has obviously never had a rat infestation. They can swim, dig several feet down, chew through concrete, plastic, wood, drywall, and otherwise go to amazing destructive measures to get to a heat or food source. Unlike mice, keeping your food in the cupboard or Tupperware containers is useless as they chew right through them, and destroy your home's foundation while they are at it. No, rats are not at all like wild horses, cats, or deer. Rats are a special kind of hell.
If you need an ecological reason. The destructive urban rats are an invasive species, not native to North America. We brought them here - and I for one applaud every effort to get rid of them.
Cats, deer, and wild horses generally won't climb walls and crawl into your house. And they don't share rats' long history of spreading disease and eating grain from storage containers. Deer are food. Horses can be tamed and used to do valuable work. Cats can be tamed and used to protect grain from rodents.
Rats are very clean animals.
Except, you know, for:
lymphocytic choriomeningitis ...but except for those, VERY CLEAN!
bubonic plague
typhus
hantavirus
leptospirosis
rat-bite fever (it's a real thing; look it up)
salmonellosis
Colorado tick fever
cutaneous leishmaniasis
If technologically superior aliens come here wanting earth (or whatever), I don't particularly care about how humane their human-extermination methods are. I'm more concerned about if our alien-extermination methods are effective enough to stop them, and perhaps whether or not our methods of alien-extermination are MORE effective than their methods of human-extermination.
No one is trying to kill your pets. Rats are filthy and violent. They destroy food, spread disease, and even hurt the animals we WANT to keep around and well cared for. Varmints are going to be killed, if you don't do that you don't even have a civilization.
You definitely speak like someone who has never had to deal with an actual infestation, or thought much about that situation much.
Actually asphyxiation by breathing near pure CO2 isn't bad. It's remarkably swift.
Likely better than thallium or anticoagulants like warfarin. There isn't a perfect way to kill rats, but this seems like an improvement.
I'm not sure why they are using dry ice rather than just a tank of compressed CO2.
Likely because the dry ice is cheaper, easier, and more effective. It also requires less equipment and training.
Or pure N2 for that matter
N2 is lighter than air, and you need enough of it to completely displace the air. CO2 is dense, and even denser when it is at -109F, so it will flow into the burrows. It is toxic at about 7%.
which eliminates the stress response entirely
I doubt if most people with a rat infestation consider this to be a critical criteria.
> If there's a bug, I catch it and release it outside
What if there's fifty bugs? What if there's a hundred bugs and a dozen mice? Someone is keeping your apartment free of bullshit parasitic creatures that spread disease and filth. It's not you, apparently, but someone is doing the fucking job out of your sight.
> Fleas.
No, rats. The fleas are just a vector to get it from rats to people. The fleas come with the rats.
We better hope we don't encounter aliens that feel the same way about us and see us as pests on "their" new planet.
What is your point? That aliens will treat us better if we are nice to rats?
Real life is not like Star Trek.
I really do not think there is a solution that involves not killing them. If you stopped killing rats for 4 months there would literally be something like a hundred times as many rats as there were before. They would explode out of the sewers and eat small children and babies in their cribs. Their ability to reproduce exponentially would mean that every edible morsel of food in the area, whether human, pet, or more generic foodstuff, would necessarily be converted into more rats within a few years time.
Troll is not a replacement for I disagree.
What if there's fifty bugs? What if there's a hundred bugs and a dozen mice? Someone is keeping your apartment free of bullshit parasitic creatures that spread disease and filth. It's not you, apparently, but someone is doing the fucking job out of your sight.
And, it's probably a cat. Which directly answers one of the questions posed in the summary.
It's not quite that simple. What works will for pigs does not work well for all animals. I use a number of animal models, including mice and rats, in research studies. CO2 asphyxiation is the currently preferred method for mice and rats for humane euthanasia, provided the exposure concentration is kept low. Argon has been shown to induce aversion in rats (as an indicator of pain), while N2 exposure has had mixed results in varied studies. It's possible N2 is more humane, if the mix was correct, but that is far from clear to me, and I am roughly familiar with current best practices and research (yes, there is research on the most humane way to kill animals).
Of course, what is done in a controlled lab environment is distinct from dropping a brick of CO2 into a warren. Extremely high concentrations (>40% or so if I recall correctly) of CO2 can induce burning sensation, while lower concentrations induce unconsciousness without apparent aversion in rodents. I'm really not clear on exactly it would happen in an uncontrolled environment, but it is far from clear to me the N2 would be a better option.
There are better ways. When I had some yellow jackets move in, I blasted their nesting area with cinnamon powder. Apparently, they like the smell about as much as humans like a garbage dump.
As for termites, yeah, sometimes you have to resort to poison. It's about a measured response, not no response.
Although it's an old technology, older than the 3.5 mm audio jack even, the ordinary mousetrap is humane, effective, reusable, and available in multiple sizes. They kill instantly; you'll never find a mousetrap with a live rodent wiggling around in it.
The glue boards, on the other hand, are pretty gross. The rat sticks to them and then you toss the thing into the trash, which always struck me as somewhat psycho. Sometimes people buy them without it dawning on them they're going to end up throwing a live mammal into the garbage. I knew one guy who came across a starving mouse wiggling in the glue, was overcome by an unexpected burst of empathy, and spent the next half hour making a mess outside with rubbing alcohol trying to pry it off without tearing any limbs.
CO2 is toxic?
Yes. CO2 forms carbonic acid when it is dissolved in water, and acidifies the blood to lethal levels when above about 7%. With conditioning you can tolerate slightly higher levels.
No. You're talking MONOXIDE.
CO is much more toxic than CO2, but either can kill you.
CO2 only deprives the air of usual ratio of oxygen, and is not notice in itself.
No. This is wrong. If you add 7% CO2, you still have about 18% O2, which is more than enough for a healthy person. It is the CO2 that kills you, not the absence of oxygen.
Asphyxiation via C02 is an absolutely HORRIBLE way to die, regardless of the creature. There's a reason Carbogen (C02/Oxygen mix) is used to induce anxiety to test out anxiolytics. I mean I get that they need to solve the infestation problem but can't we choose a method that isn't also a completely inhumane method?
This is just not true. Low concentrations of CO2 can cause distress. High concentrations are fast and painless.
There have been lake and volcanic outgassing events which release massive amounts of CO2 and it kills people and animals where they stand, in seconds.
See the Lake Nyos incident to see how CO2 kills.
And here's the final report on the incident from the USGS (PDF): "In this incident, asphyxia resulted from the displacement of normal atmosphere (approximately 21 percent oxygen) by a cloud of carbon dioxide gas. Under such circumstances, victims will literally "drop in their tracks" after taking a few breaths and experience no feeling of suffocation. The actual mechanism of death is believed to be a paralysis of the respiratory centers in the brain by very high concentrations of carbon dioxide. Lethal levels of carbon dioxide are in the range of 8 to 10 percent (Sittig, 1985)." - pp. 18-19
Also: "Additionally, many victims were found in their beds still covered by bed clothing. Victims found outside appeared to have collapsed suddenly without substantial movement. Animals were described as "dead in their tracks" in herds rather than dispersed." - page 17
An accepted humane way to kill lab animals is with high concentrations of CO2. The key is "high concentrations."
This concept, of dry ice generating carbon dioxide which flows down into holes at high concentrations, is actually brilliant and humane.
Any aliens capable of crossing interstellar distances are almost certainly quite capable of exterminating humanity without getting anywhere near close enough for us to strike back. Heck, just lob a few largish asteroids at our major cities and wait for a year or two for the resulting "nuclear" winter and general chaos to starve most of the population, and probably cause the near total collapse of civilization in the process. The survivors would then be in no position to fight the hordes of von-neuman kill-bots that had been replicating while they waited.
And that's assuming technology scarcely more advanced than what we already have. Given the age of the galaxy, any aliens we encounter here are as likely to be thousands or millions of years more advanced than us.
The entire "humanity overthrowing alien conquest" meme is a storyteller's fantasy with no rational basis in reality.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
>They kill instantly; you'll never find a mousetrap with a live rodent wiggling around in it.
Bullshit. I've had many a mousetrap go off when I was nearby, that left the mouse screaming for several minutes before it died. Yes, my squeamishness exceeds my compassion, and I failed to finish them off more promptly by other means. Not my proudest self-realization.
Totally agree about the glue traps though, those things are just evil. If you're going to murder something, you should at least aim for doing so humanely.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
House centipedes. The grey-brown kind with lots of long thin legs.
They're completely harmless to humans, even kinda cute for a bug, and are voracious predators against virtually all the home-infesting insects that we dislike, including termites, cockroaches and nigh-indestructible bedbugs. They can even become kind of friendly as they mature through their seven-year lifespan, if you're into befriending your "guard dogs".
I'm not above squishing particularly annoying bugs, but fostering a population of human-benign predators is far more effective, and controls potential infestations long before you even notice you've been invaded.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Obviously, you've never used a MacBook in defense of your home planet.
If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
Honestly, dry ice is probably a LOT more humane than rat poison.
The whole reason rat poison functions is because rats don't have a gag reflex. Once they "acquire" something by eating it, the only way to get rid of it is via full digestion and pooping it out.
So they can't puke up rat poison. This gives the toxin plenty of time to kill the rat, especially with their high burning metabolism.
Dry ice evaporates into CO2 and knocks the rats out. Then, as the CO2 levels climb, kills them.
If you've ever seen the "Crazy Russian Hacker" video where he builds a work bucket-based "air conditioner" and uses dry ice instead of regular ice? DUMB.
This explains it in excruciating detail. https://youtu.be/YIgV2Q8Leh0
Chas - The one, the only.
THANK GOD!!!
Not directly, but they are the carrier for a very common parasite, T.gondii. It's endemic just about everywhere domestic cats can be found. It infects humans too, though it can't reproduce in them. In humans it concentrates in the brain, usually to symptoms so mild they go unnoticed - the victim just feels tired and slightly feverish for a short time - but the presence of the parasite has been linked to a number of mental health conditions.
T.gondii is notable for influencing host behavior - it causes rats to become less fearful, increasing the chance of getting caught by a cat and consumed so the parasite can continue it's life cycle in a cat. The same mechanism of altering brain chemistry that causes rats to become less fearful is also active when it infects humans, but as it evolved to mess with rat brains the effect on humans is different.
As a matter of public health, it would be wise to place restrictions on domestic cats - at the very least to deny them access to outdoors areas where they may have contact with wild animals. But cats are cute and everyone loves them, so such measures are politically non-viable.
Yeah the little shits will hit you with a frying pan first chance they get
Just a few EMPs, and their kill-bots to wipe up the confused meatsacks left behind. No nukes, that'd spoil their conquest. Unless they mastered anti-matter bombs. Though radioactive, the radiation from those is quite short lived.
Though, I want to see the aliens with an orbital drill. Drill to the core, heat it up 10,000 degrees, watch the continents melt, while they reform the planet in our image. When the construction workers make a house, they don't exterminate the ants first. They leave that to the bulldozers.
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