5 ms·

Increasing rat numbers in cities are linked to climate warming, urbanization

60 points by rntn 2y ago

01HNNWZ0MV43FF 2y ago
Better speed up urbanization to fix the climate then
jlnthws 2y ago
The sharp rise in the rat population in my city coincides with a new regulation requiring food waste to be placed in a thin, dedicated bag outside. Since collection is delayed, the waste spoils, providing an easy food source for pests. It did not coincide with climate warming, at least not in my city.
- conception 2y ago
  Why not both?
- deleted 2y ago
  [deleted]
- analog31 2y ago
  In the town where I grew up, the city code required every house to have a disposal in the kitchen. The code stated that the rule was intended to help control rats. Every house I've lived in had one, but coverage is spotty in cheap rental units. I've never had to throw food waste in the trash.
  - buildbot 2y ago
    FYI, don’t dispose of food waste in a garbage disposal. It’s good for dealing with a small amount of food, but pipes are not designed for mass undigested food waste.
    - tlb 2y ago
      I've been doing it for many years in my house with no problem. Are you claiming that someday something will go terribly wrong and I'll regret it?
      - buildbot 2y ago
        Unironically, yes - You can find many sources online by googling it: https://www.stansac.com/blog/are-garbage-disposals-bad-for-plumbing https://www.stansac.com/blog/are-garbage-disposals-bad-for-p... It could be that it never happens, but most food waste should go in the trash or ideally compost.
        masfuerte 2y ago
        So what are they for? If you scrape your plates so there are only tiny bits of soft food going down the drain you don't need a garbage disposal anyway. I don't have one and I've never had a blockage.
        analog31 2y ago
        Food waste. Chase it with a reasonable amount of water. I've never had a drain clog due to food waste. Hair in bathtubs, yes.
        dghlsakjg 2y ago
        Someone selling a convenience product does not necessarily mean it is not flawed. The company that sells you a garbage disposal doesn’t really care if there’s plumbing issues ten years down the line, or if the waste treatment plant can’t handle it, they already got paid. Another example of this in the plumbing world is flushable wipes. They cause tons of issues in plumbing systems.
        tlb 2y ago
        A clog doesn't quality as something going terribly wrong. Empirically, my plumbing costs are $300 over 10 years. By comparison, rats are actually a big problem in the deep wooded suburbs. We spend a lot more on exterminators, rat traps, poison, and mesh covers to keep them out of the house. Rats smell bad, scare the girls, attack the chickens, spread garbage around the pickup area, spread fleas to the dogs, and are a nontrivial vector for serious human diseases. So given that rats are a bigger problem than clogs under my current policy of scraping plates down the disposer, I should probably do it even more.
DiscourseFan 2y ago
Well, if the rats can eat trash bags and walls and still thrive, I'm sure the microplastics aren't going to kill us.
- croes 2y ago
  Rats have a higher reproduction cycle, so I wouldn’t count on us.
- tlb 2y ago
  Rats only live a few years, so they're not a good model for long-term effects. For instance, if microplastic exposure over 60 years causes dementia, it won't affect rats.
- beachy 2y ago
  Rats also eat electrical cable insulation so I wouldn't use them as guidance for your diet.
  - DiscourseFan 2y ago
    You'll see
mnky9800n 2y ago
I am not convinced by the plots presented in this paper but I suppose i am not a specialist on rat-climate interactions so I could be wrong.
- deleted 2y ago
  [deleted]
amarant 2y ago
Am I the only one who read this headline to mean that rats were causing global warming at first? I had to do a double take on this one
- bombcar 2y ago
  It's pirates, not rats.
tengbretson 2y ago
Is latitude even a strong corelate of rat population?
- ojhughes 2y ago
  Malmö, Sweden has a major rat problem so I would say no https://www.thelocal.se/20240313/malmo-calls-in-team-of-ferrets-to-weed-out-rats-ahead-of-eurovision https://www.thelocal.se/20240313/malmo-calls-in-team-of-ferr...
GenerocUsername 2y ago
The magic of climate science is they literally use correlation as evidence of causation. Climate change getting worse means anything else getting worse at same time can be bucketed into climate change.
- nullc 2y ago
  Your comment might sound trite to some but is not without a basis. I recently followed a rabbithole on media reports that the recent California wildfires are due to climate change. The underlying study driving the report worked like this: They took a time series of the number of acres burned each year in a part of northern California and used a regression to predict it based on a number of climate figures-- air dryness, wind speed, mean temp, max temp, etc. After finding coefficients for their regression they took an off the shelf counterfactual climate model that predicts the climate without human input. The difference in acres burned according to their regression were then attributed to climate change. An obvious issue, out of many, with this approach is that if you plug in any inputs with a trend over that time-- say hours spend viewing porn online-- the regression is going to end up with non-zero coefficients on it and you could walk away with conclusions like "internet porn viewing is causing wildfires". If you knew ahead of time that these climate stats were actually the main drivers of wildfire then this approach wouldn't be a crazy method to estimate what might happen under different conditions. But this approach cannot tells us if those inputs are drivers, much less the main ones. A generalization that threw in a bunch of additional predictors around population densities, forestry management data, etc. might get closer-- but the data being fit was already so sparse that it was probably already overfit. And at best the result would still only be as good as our ability to speculate and measure possible causes. The question of human climate change's impact on things like wildfires is an interesting, important, and very difficult one. I don't fault the researchers for trying a method that might say something useful, but to take that kind of result and treat it as an established fact and drive public policy from it seems foolish indeed. I'm sure that not all of these sorts of conclusion are equally dubious but unfortunately with media, politicians, and the general public so science illiterate that they're unable to engage with this research on its own terms we really can't trust that they're not without going and looking case by case.
jongjong 2y ago
Of course the increase in rat numbers in cities is caused by climate change. As the ice melts due to the seething heat caused by global warming, the melted ice-water from the arctic chills the air throughout the entire planet and so the rats get cold and they have to move closer to the cities to warm up on the hot bitumen. Also, they have to huddle up together to stay warm and thus they breed more. The heat causes cooling which creates a feedback cycle thus releasing more heat which melts everything which causes yet more cooling. This makes sense. The science is settled. Trust the science.
- Red_Comet_88 2y ago
  You forgot to add that the majority of climate scientists agree on climate change. This is important because science, like America, is a democracy. And we know democracy is the best thing ever. Period. Therefore, when groups of people agree on something (DEMOCRACY!!), it becomes an inviolable law of the universe. It wasn't until America became the world's greatest nation (thanks to democracy) that we discovered this natural phenomenon, however.
davidhyde 2y ago
During The Plague of 1665 in London they culled 200,000 cats thinking that they were the root cause. It turned out that the rats were the cause and cats were their natural predator at the time. So they made things worse. https://www.bbc.co.uk/bitesize/articles/zcwssk7 https://www.bbc.co.uk/bitesize/articles/zcwssk7 The OP article does mention cats as a predator. Insignificant compared to the medieval times. Still interesting. > “Parsons et al. (56) documented less than a 1% predation rate between feral cat carnivores and rats in an urban setting.”
- pantalaimon 2y ago
  I’m not surprised, rats are way too big for the average cat to deal with.
  - chopin 2y ago
    We had a rather smallish cat who loved killing rats.
y-c-o-m-b 2y ago
> The most promising integrated pest management (IPM) strategies focus on making the urban environment less conducive for rats rather than outright removal of rats already there I live in the suburbs and in the last few years have seen an exploding rat population outdoors on my property. It began when my neighbors got chickens back in 2020; when home-steading and DIY food management began taking off. They ended up eventually removing the chickens and scraps, but the rats stayed and their population keeps growing despite the removal of food. I've trapped and killed SO many of these pests, but they keep increasing and each generation seems to be smarter about traps than the previous. The traps have become ineffective at this point. I've tried many of the suggestions seen on Youtube and they fail or some of them are just downright messy/impractical (the bucket). The most effective solution I came up with so far is building a custom wooden box that leaves just a small opening (like a tunnel) for the rat's head to get into to reach the bait. I used peanut butter as bait and a snap trap inside the box. I then cover the wooden box with leaves and stuff. This worked for a few months, but unfortunately it's not working any longer. On the last occasion it worked, the rat in the trap got cannibalized by another larger rat. Since then, I can see on my camera that the rats approach the trap, but they never enter. I've tried relocating it and everything, no luck.
- teslabox 2y ago
  My neighbor has a live rat trap that he doesn't need to bait anymore. The rats are doing their thing exploring, they go into the trap looking for food, and triggers the trap mechanism. When he finds a rat in his trap, he removes it to the woods outside of our neighborhood. Senestech [0] sells an EPA-approved poison that only targets the rat's ability to reproduce. I mentioned this company previously [1], looks like their product line has expanded in the last year or two. [0] https://www.senestech.com https://www.senestech.com [1] https://news.ycombinator.com/item?id=19233500 https://news.ycombinator.com/item?id=19233500 Edit: My grandfather had a semi-feral cat that he encouraged to stay around his cabin.
metalmangler 2y ago
living in an old farm house, where rodents can be a problem, with feed and manure and old buildings providing , food and shelter for rats and mice, this year is exceptionaly cold,and now everything is frozen solid, so rodents can dig and tunnel, and all the water is frozen, so the rodents are having a hard time, invading looking for food and water and warmth, and I am doing my best to be inhospitable, rat, bat, splat. Also the preditors are finding it easier to get them as rodents are forced to expose themselves, I even had a close encounter with an ermine, which is one tiny sleek, fancy killing machine, huge eyes for the size of the head. Rats can not survive outside of areas without human development in areas with hard winter freezes, and face heavy predation by snakes further south, so are again limited to human and snake(other preditor) free areas, like islands. Also rats are essentialy imune to poisons that were deadly to them, and are likely becoming imune to whatever is thrown at them now. So numbers will be up, and the reasons for that will vary. I dont like rats at all, and study them, as I hunt them, and other vermin.
wakawaka28 2y ago
Yeah and global warming is due to the steep decline in the number of pirates over the last hundred years. Keep cranking out the misleading clickbait, you propagandists.

60 points by rntn 2y ago

Better speed up urbanization to fix the climate then

The sharp rise in the rat population in my city coincides with a new regulation requiring food waste to be placed in a thin, dedicated bag outside. Since collection is delayed, the waste spoils, providing an easy food source for pests. It did not coincide with climate warming, at least not in my city.

conception 2y ago
Why not both?
deleted 2y ago
[deleted]
analog31 2y ago
In the town where I grew up, the city code required every house to have a disposal in the kitchen. The code stated that the rule was intended to help control rats. Every house I've lived in had one, but coverage is spotty in cheap rental units. I've never had to throw food waste in the trash.
- buildbot 2y ago
  FYI, don’t dispose of food waste in a garbage disposal. It’s good for dealing with a small amount of food, but pipes are not designed for mass undigested food waste.
  - tlb 2y ago
    I've been doing it for many years in my house with no problem. Are you claiming that someday something will go terribly wrong and I'll regret it?
    - buildbot 2y ago
      Unironically, yes - You can find many sources online by googling it: https://www.stansac.com/blog/are-garbage-disposals-bad-for-plumbing https://www.stansac.com/blog/are-garbage-disposals-bad-for-p... It could be that it never happens, but most food waste should go in the trash or ideally compost.
      - masfuerte 2y ago
        So what are they for? If you scrape your plates so there are only tiny bits of soft food going down the drain you don't need a garbage disposal anyway. I don't have one and I've never had a blockage.
        analog31 2y ago
        Food waste. Chase it with a reasonable amount of water. I've never had a drain clog due to food waste. Hair in bathtubs, yes.
        dghlsakjg 2y ago
        Someone selling a convenience product does not necessarily mean it is not flawed. The company that sells you a garbage disposal doesn’t really care if there’s plumbing issues ten years down the line, or if the waste treatment plant can’t handle it, they already got paid. Another example of this in the plumbing world is flushable wipes. They cause tons of issues in plumbing systems.
      - tlb 2y ago
        A clog doesn't quality as something going terribly wrong. Empirically, my plumbing costs are $300 over 10 years. By comparison, rats are actually a big problem in the deep wooded suburbs. We spend a lot more on exterminators, rat traps, poison, and mesh covers to keep them out of the house. Rats smell bad, scare the girls, attack the chickens, spread garbage around the pickup area, spread fleas to the dogs, and are a nontrivial vector for serious human diseases. So given that rats are a bigger problem than clogs under my current policy of scraping plates down the disposer, I should probably do it even more.

DiscourseFan 2y ago

Well, if the rats can eat trash bags and walls and still thrive, I'm sure the microplastics aren't going to kill us.

croes 2y ago
Rats have a higher reproduction cycle, so I wouldn’t count on us.
tlb 2y ago
Rats only live a few years, so they're not a good model for long-term effects. For instance, if microplastic exposure over 60 years causes dementia, it won't affect rats.
beachy 2y ago
Rats also eat electrical cable insulation so I wouldn't use them as guidance for your diet.
- DiscourseFan 2y ago
  You'll see

mnky9800n 2y ago

I am not convinced by the plots presented in this paper but I suppose i am not a specialist on rat-climate interactions so I could be wrong.

deleted 2y ago
[deleted]

amarant 2y ago

Am I the only one who read this headline to mean that rats were causing global warming at first? I had to do a double take on this one

bombcar 2y ago
It's pirates, not rats.

tengbretson 2y ago

Is latitude even a strong corelate of rat population?

ojhughes 2y ago
Malmö, Sweden has a major rat problem so I would say no https://www.thelocal.se/20240313/malmo-calls-in-team-of-ferrets-to-weed-out-rats-ahead-of-eurovision https://www.thelocal.se/20240313/malmo-calls-in-team-of-ferr...

GenerocUsername 2y ago

The magic of climate science is they literally use correlation as evidence of causation. Climate change getting worse means anything else getting worse at same time can be bucketed into climate change.

nullc 2y ago
Your comment might sound trite to some but is not without a basis. I recently followed a rabbithole on media reports that the recent California wildfires are due to climate change. The underlying study driving the report worked like this: They took a time series of the number of acres burned each year in a part of northern California and used a regression to predict it based on a number of climate figures-- air dryness, wind speed, mean temp, max temp, etc. After finding coefficients for their regression they took an off the shelf counterfactual climate model that predicts the climate without human input. The difference in acres burned according to their regression were then attributed to climate change. An obvious issue, out of many, with this approach is that if you plug in any inputs with a trend over that time-- say hours spend viewing porn online-- the regression is going to end up with non-zero coefficients on it and you could walk away with conclusions like "internet porn viewing is causing wildfires". If you knew ahead of time that these climate stats were actually the main drivers of wildfire then this approach wouldn't be a crazy method to estimate what might happen under different conditions. But this approach cannot tells us if those inputs are drivers, much less the main ones. A generalization that threw in a bunch of additional predictors around population densities, forestry management data, etc. might get closer-- but the data being fit was already so sparse that it was probably already overfit. And at best the result would still only be as good as our ability to speculate and measure possible causes. The question of human climate change's impact on things like wildfires is an interesting, important, and very difficult one. I don't fault the researchers for trying a method that might say something useful, but to take that kind of result and treat it as an established fact and drive public policy from it seems foolish indeed. I'm sure that not all of these sorts of conclusion are equally dubious but unfortunately with media, politicians, and the general public so science illiterate that they're unable to engage with this research on its own terms we really can't trust that they're not without going and looking case by case.

jongjong 2y ago

Of course the increase in rat numbers in cities is caused by climate change. As the ice melts due to the seething heat caused by global warming, the melted ice-water from the arctic chills the air throughout the entire planet and so the rats get cold and they have to move closer to the cities to warm up on the hot bitumen. Also, they have to huddle up together to stay warm and thus they breed more. The heat causes cooling which creates a feedback cycle thus releasing more heat which melts everything which causes yet more cooling. This makes sense. The science is settled. Trust the science.

Red_Comet_88 2y ago
You forgot to add that the majority of climate scientists agree on climate change. This is important because science, like America, is a democracy. And we know democracy is the best thing ever. Period. Therefore, when groups of people agree on something (DEMOCRACY!!), it becomes an inviolable law of the universe. It wasn't until America became the world's greatest nation (thanks to democracy) that we discovered this natural phenomenon, however.

davidhyde 2y ago

During The Plague of 1665 in London they culled 200,000 cats thinking that they were the root cause. It turned out that the rats were the cause and cats were their natural predator at the time. So they made things worse. https://www.bbc.co.uk/bitesize/articles/zcwssk7 https://www.bbc.co.uk/bitesize/articles/zcwssk7 The OP article does mention cats as a predator. Insignificant compared to the medieval times. Still interesting. > “Parsons et al. (56) documented less than a 1% predation rate between feral cat carnivores and rats in an urban setting.”

pantalaimon 2y ago
I’m not surprised, rats are way too big for the average cat to deal with.
- chopin 2y ago
  We had a rather smallish cat who loved killing rats.

y-c-o-m-b 2y ago

> The most promising integrated pest management (IPM) strategies focus on making the urban environment less conducive for rats rather than outright removal of rats already there I live in the suburbs and in the last few years have seen an exploding rat population outdoors on my property. It began when my neighbors got chickens back in 2020; when home-steading and DIY food management began taking off. They ended up eventually removing the chickens and scraps, but the rats stayed and their population keeps growing despite the removal of food. I've trapped and killed SO many of these pests, but they keep increasing and each generation seems to be smarter about traps than the previous. The traps have become ineffective at this point. I've tried many of the suggestions seen on Youtube and they fail or some of them are just downright messy/impractical (the bucket). The most effective solution I came up with so far is building a custom wooden box that leaves just a small opening (like a tunnel) for the rat's head to get into to reach the bait. I used peanut butter as bait and a snap trap inside the box. I then cover the wooden box with leaves and stuff. This worked for a few months, but unfortunately it's not working any longer. On the last occasion it worked, the rat in the trap got cannibalized by another larger rat. Since then, I can see on my camera that the rats approach the trap, but they never enter. I've tried relocating it and everything, no luck.

teslabox 2y ago
My neighbor has a live rat trap that he doesn't need to bait anymore. The rats are doing their thing exploring, they go into the trap looking for food, and triggers the trap mechanism. When he finds a rat in his trap, he removes it to the woods outside of our neighborhood. Senestech [0] sells an EPA-approved poison that only targets the rat's ability to reproduce. I mentioned this company previously [1], looks like their product line has expanded in the last year or two. [0] https://www.senestech.com https://www.senestech.com [1] https://news.ycombinator.com/item?id=19233500 https://news.ycombinator.com/item?id=19233500 Edit: My grandfather had a semi-feral cat that he encouraged to stay around his cabin.

metalmangler 2y ago

living in an old farm house, where rodents can be a problem, with feed and manure and old buildings providing , food and shelter for rats and mice, this year is exceptionaly cold,and now everything is frozen solid, so rodents can dig and tunnel, and all the water is frozen, so the rodents are having a hard time, invading looking for food and water and warmth, and I am doing my best to be inhospitable, rat, bat, splat. Also the preditors are finding it easier to get them as rodents are forced to expose themselves, I even had a close encounter with an ermine, which is one tiny sleek, fancy killing machine, huge eyes for the size of the head. Rats can not survive outside of areas without human development in areas with hard winter freezes, and face heavy predation by snakes further south, so are again limited to human and snake(other preditor) free areas, like islands. Also rats are essentialy imune to poisons that were deadly to them, and are likely becoming imune to whatever is thrown at them now. So numbers will be up, and the reasons for that will vary. I dont like rats at all, and study them, as I hunt them, and other vermin.

wakawaka28 2y ago

Yeah and global warming is due to the steep decline in the number of pirates over the last hundred years. Keep cranking out the misleading clickbait, you propagandists.