How some cities became rat-free zones | Hacker News Reader

How some cities became rat-free zones

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92 pointstomohawk107 comments

Generally I think that we should manage animals in the most humane way possible (e.g. we likely cannot have lions roaming around cities but that doesn't mean we should just wipe them out).

However, it seems like rodents are a difficult case: As I understand it the basic evolutionary strategy for most rodents is "breed prolifically in order to offset a very high mortality rate". In that case it seems like extermination is effectively the "natural" way to manage them. I don't think it would be possible to round up rats and put them in shelters the way that we do stray dogs.

What alternative method of managing rodent populations would you advocate?

Abstinence

Not gonna lie, this post made my day. Well done sir/madame!

Allowing them to live in our presence and not trying to kill them? Rats are largely scavengers, their involvement in, e.g. black plague, has been disproven. If you don't leave food out and available, they won't eat it. In many countries around the world people live in harmony with other animals and don't try to wipe them out just because they are in the same space. Not to mention the amount of toxic poisons that end up harming us more than the rats that we are dumping int our own habitat to try to kill the rats.

It's not much different than insects. We've chosen a few "pest" insects as the scapegoat/enemy and have bent over backwards trying to exterminate them. As a result, we've decimated all insect populations as collateral damage, severely damaging our own habitat, environment, and ecosystem, and again, poisoning ourselves in the process. Because... Everyone eats insects, and once there are no insects, there's nothing for them to eat!

Same thing with bacteria. We've decided that sterility is the way to go, and gone on a mad spree trying to kill all bacteria, forgetting that bacteria is how we digest food, so again, poisoning ourselves and damaging our own health, threatening ourselves in the process.

These are all living organisms that we are closely related to, sharing the same environment as us, and anything we do to them comes back to us.

Not only that, but our bodies are tuned over millions of years to coexist with them, and a sterile environment with all kinds of synthetic poisons in it, once again, fucks us up.

There is also the issue that computers and AIs are learning from us the way children learn from their parents, and will one day treat us the same way that we treat the "lower" species.

I definitely agree that trying to just eliminate nature from our cities is going to have negative consequences. And from what I understand, the mechanisms behind many of the ways we kill rodents (e.g. anticoagulant poison and sticky paper) seem inhumane.

I'll have to look into if there have been studies on more systemic approaches to managing animal populations. Things like changing how/where food waste is stored.

Would you oppose lethal approaches to rodent control if they were more limited and directed? For example, a warehouse getting a cat or setting out some mouse traps.

I have this book:

https://www.amazon.com/Common-Sense-Pest-Control-Least-Toxic...

Sounds like what you're looking for. I've used its recommendations in the house I built, with good results. (For example, instead of foam I used a metal sill plate, which prevents insects from coming up through cracks in the foundation into the wood structure.)

Interesting! What kind of metal did you use and did you have to install some kind of sacrificial anode to ensure that it won't oxidize away over the decades?

I used stainless steel sheet. Where the anchor bolts were, a largish hole was punched in the sill plate so the stainless wasn't in contact with the iron, which would have resulted in galvanic corrosion.

The contractor groused about it, because he wasn't used to doing things that way. But he got excited about it after a while, and on his own fabricated stainless steel inserts that the windows would fit into that would prevent any leaks and rot around the windows. He was pretty proud of his work :-)

Another thing the book recommended was putting ground glass into the concrete mix, as rats won't chew it. But I didn't go that far.

The main thing is to make sure any gaps and vents have wire screens. Mice can get in where the plumbing enters the house, you can stop that by ramming steel wool between the pipe and the house.

Cats are very effective, and their smell acts as a deterrent.

Traps and poison are inhumane, cruel, and just bad karma, and usually come back to bite us somehow.

I think the solution is to tolerate and even appreciate the rats, and learn to share space with them.

Why is a rat trap less humane than intentionally bringing in a predator known for torturing its prey?

Depends on the trap I would say. One that generally rapidly kills is fine but say sticky traps are cruel. Traps where the animal is stuck in place unable to move and slowly dies of dehydration/starvation that is just sadistic.

That's a pretty popular viewpoint to be honest. Glue traps aren't even particularly effective, and neither are they particularly reusable. So in addition to being cruel they just aren't a good deal for the money you'll spend.

Drown traps (using any number of mechanisms to dunk rodents into a bucket of water from which they cannot escape) might be a bit rough ethically though I think much better than glue traps. Additionally they're many times more effective, fully re-usable, and you can make them basically for free with a few scraps laying around in your garage. One method that works well on mice and other small rodents (though not so much on norway rats which are incredibly clever) is as simple as floating a layer of seeds on top of the water. The rodents jump in to get the seeds, not realizing that the seeds were floating on water. A bag of bird seed, a bucket and some water are all you need for that sort of trap and although death isn't instant, it's a lot faster than with a glue trap.

Your assertion that rats weren't involved in the spread of the black plague is misleading.

Rats do spread disease. Some experts believe they were not the vector for the black plague, but there are several other (many of which are quite recent) outbreaks where rats have unquestionably spread disease.

Take a look for yourself:

https://www.cdc.gov/rodents/diseases/direct.html

Personally I believe we should preserve human health over rat health, and a good way of doing that is to exterminate rats.

> "It's not much different than insects. We've chosen a few "pest" insects as the scapegoat/enemy and have bent over backwards trying to exterminate them. As a result, we've decimated all insect populations as collateral damage, severely damaging our own habitat, environment, and ecosystem, and again, poisoning ourselves in the process. Because... Everyone eats insects, and once there are no insects, there's nothing for them to eat!"

I kindly invite you to rent a room at the shittiest motel in town and learn to live and let live with bed bugs.

Also, fuck mosquitos.

I’m not a fan of spiders or cockroaches. I can adapt my behavior so we rarely interact.

But, uh, miserable bloodsuckers-I don’t think there is any common ground for us to share.

Mosquitos are a legitimate, serious problem in some parts of the world as fatal disease vectors. I don't know enough about their role in the ecosystem to know whether it's okay to wipe them out, but considering the number of human lives they claim every year through spreading disease I'd happily go that route myself.

same with ticks. Fuck ticks. blood sucking assholes spreading dissease. Some species can cause paralyses in victims, others can induce meat allergyes, many carry a verity of hellish viral bacterial and protozoen infections.

As far as I know birds eat them. A lot. But then again, birds eat other stuff, too.

I could live with them, they should just come down and take my blood.

But all they do is buzzing around my head when I try to sleep!

I am amazed at how efficient rats are. I put a garbage bag in my shed and 3 days later the only thing that was left was the plastic.

The government in their infinite wisdom hatched out a scheme were everyone has to pay per kilogram of produced waste so a lot of people were just dumping their trash. It was a 24/7 buffet for rats. Then, as only a country that has literally too much money can do, they sent out inspectors on to the streets to sift through the bags and fine people.

We have lions roaming around my city. That you don't see them doesn't mean they aren't there. Large predators can and do coexist with humans in relatively urban environments.

https://www.tricitynews.com/news/cougar-warning-issued-to-be...

https://bc.ctvnews.ca/coquitlam-cougar-sighting-residents-ad...

https://www.nsnews.com/news/north-van-cougar-sightings-promp...

Lions are everywhere in some parts of Vancouver. It is rare that one must actually be put down. We can get along.

Best thing for keeping everyone alive:

https://www.mec.ca/en/product/4007-144/Bear-Bangers-%286-Pac...

Nonsense. In the past few months a hiker was killed, a young child attacked, and multiple other people were attacked. We can't "get along". The best thing for both cougars and humans is to stay out of each other's way.

And how many were killed by cars in the same period? Of many thousands of interactions, most unnoticed by the humans, only a very tiny few resulted in violence.

I have lived my whole life in areas with healthy cougar populations (rural and urban). I have never seen one. In the same time period, I have seen dozens of coyotes, black bears, big horn sheep and mountain goats. It's said you only see them when it is too late.

I have never heard of a cougar being hit by a car. I just don't see a car sneaking up on a cougar.

I do however agree that they aren't a real threat to most people. A healthy cougar will avoid humans, generally. I camped in a tent immediately after a cougar sighting. I was still more worried about a curious bear looking for food.

I think cougars scare people because they are large, basically invisible, extremely effective ambush predators. They will attack and kill pets and infants. Joggers also seem to trigger their predatory responses.

That is understandably terrifying. One of the few cases where a cougar needs to be destroyed is when it has lost its fear of people. Very rare, but very bad for the other people and cougars in the area.

I think education can go a long way. They are not evil baby eaters, they are beautiful animals with predictable predator responses. If you see one, don't try and run away! Maybe reconsider that solo wilderness jog with earbuds.

He also perhaps meant actual lions, not cougars. An actual lion also weighs roughly twice as much as a cougar and isn't solitary and/or shy around humans.

Even with cougars there are some problems, with actual lions they would need to be constantly tracked, sedated and relocated.

I don't think we should lump all rodents together. Squirrels, for instance, can reasonably be kept out of our houses and buildings, especially out of the living areas. Even if one finds a way into an attic or crawlspace that you forgot to squirrel proof, it is going to be going out to forage, and so hawks, cats, dogs, and cars keep the population down.

Urban squirrels for the most part live beside us, where as rats and mice live with us, and so the later are much more likely to need to be managed.

It's worth mentioning that cities traditionally were shared with free-roaming cats and dogs. It's only recently that we've taken them off the streets.

I'm often dismissed as some kind of a troll for advocating the reintroduction of street animals in my local town. But cats and dogs were instrumental in the development of civilisation. They control vermin, they deter wild animals, they reduce food waste, they act as an alert against violent antisocial behaviour.

We need to get rid of the idea that cities belong only to humans. Many animals belong in city ecosystems.

In Turkey, having free roaming cats and dogs is still very much part of the culture, and I hope it never goes away.

People take care of them, and the government too, so you will almost never see a cat/dog aggressive towards human or very sick.

An interesting take. As a cyclist, cats generally don't bother me, but dogs can be a massive nuisance. It's no fun being chased by a snarling dog on a steep incline. I do occasionally stop and "confront" them to try to scare them away but sometimes it doesn't work.

I'm hardly ever reassured by the owner, if there is one in sight, saying that he/she doesn't bite.

I used to have one of those ultrasound gadgets but the first one I tried left the poor dog whimpering, which made me feel like crap and the second one seemed to be ignored by most dogs. To be fair this was over 10 years ago, so the devices might actually work better these days.

Not from Turkey but we do have roaming cats and dogs in the countryside back home.

My experience in Turkey is that cats and dog almost never follow you (unless you are feeding them) and don't run after you. For the most part, they are actually quite shy / don't really care about you.

My wife use to bicycle a lot in Turkey and she never had a problem with dogs and cats, but you don't see them that much in the countryside also.

Lonely dogs are not a problem but packs of stray dogs are a huge problem in the rural areas in Turkey. They are fearless and aggressive in a pack.

In principle I'd agree, but there is one small problem. They shit everywhere, and that becomes a problem in its own right.

iirc Victorian London had to find a way to dispose of something like 4 tons of horseshit a day. And horseshit is easy -- it makes brilliant compost. Cat and dog shit less so. Much less.

I never thought about this. I don't know how Istanbul manage it, there is a lot of cats but the city is quite clean for a city that size (but cleanness is also quite important in Turkish culture).

Cats are solitary hunters that rely on their prey not being aware of their presence. They generally don't shit on the street. They dig a hole and close it properly. Cats usually sniff multiple times to see if there's any trace. They're much more likely to dig up playgrounds and litter there.

Massive kitty litter boxes in all/most parks? Tongue firmly in cheek by the way.

Have you been to San Francisco lately ?

just because that was the stable state doesn't mean it is the only stable state

Cats also carry disease (toxoplasmosis), dogs in many parts of the world may carry rabies.

Mind you I'm in favour of one type of suburban animal: birds. Except feral pigeons. Also tend to be killed in large numbers by outdoor cats and window collisions.

There are many other species able to control vermin, we don't have to replace them on all the ecosystems we touch.

In the Morrocan cities I visited, there were no rats due to a large feral cat population.

Some of the cats had health problems, which was sad. I'd rather have cats than rats, but cats aren't a solution on their own.

I've read that birth control hormones work well for controlling rat populations. Dose their food supply consistently, and they die off without reproducing.

Where do you suppose those hormones go after the rats die?

It's not really possible to manage even stray/feral dogs and cats that way, if it has gotten much beyond a "stray" pets problem.

Dogs and cats, given favourable conditions, can breed up and affect an ecosystem as major predators do.

Australia, for example, has cat & dog problems on a continent-scale. Dogs are hybridising with displacing the semi-native dingos, and that basically means a totally new top predator. Cats are the number or or two threats to several vulnerable and endangered species (eg fairy penguins, in the south), and have already caused multiple extirpations.

At some point, managing these animals can't be done with a "pets" mentality. They are just feral animals that are related to pets.

There's not going to be shelters for I teoduced foxes or weasels.

If you have a varmint problem of some type, I would highly recommend using spring traps over putting out DCON or other poison. If you care about killing them kindly, a big snap that crushes their skull or breaks their neck is better than slowly dying of poison.

More importantly, if they die in your trap, you know where they are and can clean them up easily. There are few things more disgusting than finding a rat or a squirrel that has crawled off into some tight space to die, and sat there long enough in the heat for the flies and maggots to get at the corpse

Also having dead rats or mice rotting away in a hidden corner literally stinks.

Also, have a thought for the animals up the food chain, poisoned by poisoned rats and mice.

This LRB bit on rats is a good read:

> ‘Rats that survive to the age of four are the wisest and the most cynical beasts on earth,’ an exterminator told Mitchell sixty years ago. ‘A trap means nothing to them, no matter how skilfully set. They just kick it around until it snaps; then they eat the bait. And they can detect poisoned bait a yard off. I believe some of them can read.’

https://www.lrb.co.uk/v27/n06/sean-wilsey/some-of-them-can-r...

> Farms closest to the border are checked twice a year and adjacent sites once. It sounds like a lot, says Merrill

That sounds like very little, and yet they have proven results. I know people who run traps and check/reset them weekly over 10+km lines. That sounds like a lot, and yet it’s hardly denting the population. Unfortunately it’s 1080 poison that is needed. New Zealand has a vague goal of becoming pest free. This is going to be hard, and cats don’t fit with this. Perhaps dogs don’t either?

Rats can't survive outside in the winter in Alberta (or Saskatchewan). They need human buildings. The distances between farmsteads are large, at least from a rat's point of view. There is therefore a relatively large time constant between jumps from one farm to the next. Checking a couple of times per year is usually sufficient.

Fuck, I live in rat heaven- chicago. One sneaked into my bedroom last polar votex. Never knew my sweetest gentle cat had such vicious killer instinct. Flew straight out from the kitchen table and bit its neck and then proceeded to torment the poor thing for next 1/2 hr before I rescued the rat, picked it up with towels(blood still dripping) and threw it in garbage bin outside.

I decided that night to move the fuck out of chicago and will be moving out end of this year.

I’m curious where you plan to live that doesn’t have any rats.

I lived in Paris, Berlin, Tokyo. Never saw any rat where humans would go. I think I spot mice in Paris in the streets once.

They are pretty good at avoiding being seen, but they are around. Paris has more rats than humans, and Berlin has about 2/3 as many rats as humans. I haven't need good estimates for Tokyo's rat population, but there are about 5000 reports of human encounters a year (down from 20k/year in 2001).

> I haven't need good estimates for Tokyo's rat population, but there are about 5000 reports of human encounters a year (down from 20k/year in 2001).

What do you mean reports of human encounters?

I was in Tokyo a few weeks ago, and I saw some rats. I didn't report it, because who gives a shit if you see a rat in a city? I've seen rats in every city I've ever been in.

Really? I lived in Paris for a month and saw the "dératisation", and the rats. A park was so infested they had to close it temporarily.

Paris is literally crawling with them. Every park we went to last year had them in bushes, under seats and climbing on peoples possessions as we watched. I biked quite a few km while there and saw them all over the central area.

There is difference between having 'any rats' and being rat capital of usa[1]. I see them all time, everywhere here.

1.http://mentalfloss.com/article/561029/most-rat-infested-citi...

That list seems to be a roughly ordered list of cities by population. I see rats at night in most cities I spend time in.

What are your garbage bins like? Whenever I see pictures of New York they always have open, rat accessible bins and garbage bags on the street waiting for pick up that take a rat 2 seconds to get through. I'm not sure if that reflects reality but if it does then I think they're half the problem.

Even if you keep them closed homeless folk tend to have a look and leave them open.

Alberta?

Heh, I was trying to find the clip from Ratatouille about Alberta and rats but failed in my short attempt.

For context for non-Western-Canadians, there were 3 rats found in Calgary in 2018 and it was a big enough deal that there's news articles about it: https://globalnews.ca/news/4342316/rat-found-calgary-rat-fre...

Being from Saskatchewan... I guess we may have some rats here, but I've never seen one outside of a pet store.

Move to a city where coyotes live? I live in a city near a large park and have never seen a rat, but I do hear coyotes fairly often. I think these are related.

Chicago has lots of them: https://www.chicagotribune.com/news/ct-downtown-coyotes-met-...

In the outlying areas of the SF Bay Area we have both rats and coyotes. You don't see rats out on the street much but watch a dumpster full of food waste at night and you'll eventually spot them. Coyotes catch some but the rats breed quickly.

Apparently, they can go to Alberta...

Another recent rodent killing article can be found here: https://news.ycombinator.com/item?id=20019487

Disgusting animal abuse... There is place for everybody in our cities.

Meanwhile in more civilized places:

> Fat rat stuck in manhole rescued by firefighters in Germany

https://www.theguardian.com/world/2019/feb/27/fat-rat-stuck-...

Every German city has a program to deploy rat poision once or twice per year

Rat poison that travels and ends up in our own air, food, and water, and is just as effective on us as it is on them.

If it was as effective, title would be: Cities became human free.

It does cause a lot of health issues.

My dad eats the stuff.

Seriously, rat poison is an FDA-approved medication that is used to prevent blood clots. The dose makes the poison. If you get too much, you become a hemophiliac.

So it's fine when diluted.

Are you suggesting that everyone should be taking this FDA-approved medication that prevents blood clots?

"There is a place for everybody in our cities"

You mean once we destroyed their habitat anyways? All houses, buildings, roads, factories, etc, were all habitats to animals, insects, vegetation, etc, and then they were displaced or killed when the land was cleared for construction. But luckily for us, that was before we moved in or places we don't have to see it.

All the items you use are mined and manufactured in buildings or places that destroyed other life on the planet, and then will destroy more once disposed of again.

This empathy for rats seems completely misplaced.

Please don't post take HN threads further into flamewar, no matter how much you love animals.

Nationalistic flamebait is particularly unwelcome here, so no more of that please.

https://news.ycombinator.com/newsguidelines.html

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