Pioneering study finds more than 200,000 rats in Barcelona’s sewers(elpais.com)
elpais.com
Pioneering study finds more than 200,000 rats in Barcelona’s sewers
https://elpais.com/elpais/2018/09/19/inenglish/1537368873_338066.html
48 comments
A bit of context that is perhaps relevant. As some of you know, there is a political conflict between the central government of Spain and the local, pro-independence Catalan government. El País, a newspaper published in Madrid, has quite explicitly taken the central government's side a few times. I wouldn't be terribly surprised if this bit of news was singled out for publication because it's about there being potential health and safety issues in the main city of Catalonia.
I lost count after 200,003 rats :)
Do rats serve a useful (for us) purpose there? If not, can we release a rat specific poison or is that impossible without harming the entire ecosystem?
Do rats serve a useful (for us) purpose there? If not, can we release a rat specific poison or is that impossible without harming the entire ecosystem?
> can we release a rat specific poison or is that impossible without harming the entire ecosystem?
"Eradication" is a bit of a misnomer because it is not possible to actually eliminate rats from a city. The goal is to keep them from getting out of control. However bad a rat problem is, it can get much worse if unchecked.
These programs use a combination of public education, on-demand services (poison, burrow-treatments), and other interventions like city codes for proper garbage containers/handling etc.
>"Eradication" is a bit of a misnomer because it is not possible to actually eliminate rats from a city.
It’s been done before: https://www.thecanadianencyclopedia.ca/en/article/rat-contro...
It’s been done before: https://www.thecanadianencyclopedia.ca/en/article/rat-contro...
And it’s not a long way off being tried in New Zealand, which has (distant) goals of being predator free. Presumably this excludes humans.
Barcelona has very old sewers, which means there are many places for rats to gain entrance to the sewers, as well as places to live and hide. It's not a battle that's easily won.
Modern sewer systems separate storm runoff from sanitary sewers, and try to keep the sanitary sewers sealed off from animals. It's hard to change the infrastructure under a bustling city though, so most major cities tend to have the sewers they were built with, or whatever was retrofitted when it became apparent that sewage in the streets was worse than the expense of building a sewer system. However, rats are clever and do occasionally find their way in and around modern sewers as well.
Modern sewer systems separate storm runoff from sanitary sewers, and try to keep the sanitary sewers sealed off from animals. It's hard to change the infrastructure under a bustling city though, so most major cities tend to have the sewers they were built with, or whatever was retrofitted when it became apparent that sewage in the streets was worse than the expense of building a sewer system. However, rats are clever and do occasionally find their way in and around modern sewers as well.
https://www.theverge.com/2015/5/13/8592817/rat-patrol-new-yo...
The guys who do this professionally/successfully in a sparsely populated place with everyone helping and the advantage that rats can't survive outdoors don't think it's possible in cities.
Big problems with poison: Rats are harder than you think to poison, they're both sceptical of new food and adapted to survive lots of poisons Evolution will work against you and select rats that don't eat or digest your new poison You will poison lots of things you don't intend to (wild animals, pets, humans).
You can imagine an IOT solution in 50 years though (coordinating web of mechanical cats/ferrets with amazing smell/sight that just never stop hunting).
The guys who do this professionally/successfully in a sparsely populated place with everyone helping and the advantage that rats can't survive outdoors don't think it's possible in cities.
Big problems with poison: Rats are harder than you think to poison, they're both sceptical of new food and adapted to survive lots of poisons Evolution will work against you and select rats that don't eat or digest your new poison You will poison lots of things you don't intend to (wild animals, pets, humans).
You can imagine an IOT solution in 50 years though (coordinating web of mechanical cats/ferrets with amazing smell/sight that just never stop hunting).
Then you can change the target (Black Mirror: Metalhead)
One of my favorite episodes, honestly.
It was important, but ultimately so depressing that it turned me off to the series.
I know the feeling. I remember countless instances where I wanted to watch a new episode, but couldn't muster the courage to do so.
AI gun turrets in the sewers.
Not quite there, but this thing is successful. It’s a self resetting trap, with its kill attracting more target species. Refilling if after ~25 kills is more expensive that resetting a manual trap, but the labour cost is ~25x cheaper. https://goodnature.co.nz
Off topic, but you really think there arnt automatic turrets, seems very feasible today, especially in a situation like a sewer where you really dont have to worry about shooting the wrong (moving) thing.
We had automatic turrets decades ago, so the "AI" part was just me trying to be funny.
No way an army of robot cats and ferrets can be used for malicious purposes. No way...
Alberta have managed to keep rats at bay: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/All/agd...
For a government record of the development and implementation of government policy, that is a surprisingly fun read.
It's hard to imagine a public education campaign like this working today:
> Posters and brochures on rat control were widely distributed; displays were presented at local fairs, picnics and rodeos; and talks were presented to schools, 4-H clubs, agricultural societies, Chambers of Commerce and to just about anyone who would listen.
...let alone with this level of dedication from the educators:
> At a series of meetings with members of Indigenous communities, an Alberta Agriculture staff member ate warfarin-treated rolled oats while discussing rat control and the physiological effects of warfarin. He was able to effectively demonstrate the relative safety of warfarin to concerned community members, and they were able to move forward together.
It took about a decade for the program to work, but it did work:
> The number of known rat infestations in the border area increased rapidly from one in 1950 to 573 in 1955, and the numbers varied between 394 and 637 during 1956 to 1959. After 1959, the numbers of infestations dropped dramatically (Figure 3 [showing # rat infestations in Alberta hovering between 0 and 4 since 2000]). Hence, almost 10 years passed before an accumulation of training, experience and public education brought the rat problem firmly in hand.
And finally, rat control seems to be a point of genuine public pride. Something about regularly trumpeting government success in media is weird to me, but they seem to have earned it, and it's useful to keep people appreciative and aware.
> The discovery of a rat in Edmonton or Calgary receives full media coverage. In addition, the success of the program is reported by provincial or national media three or four times a year, and this success serves as a reminder to the residents that rat control is still an important program in Alberta.
Great link!
It's hard to imagine a public education campaign like this working today:
> Posters and brochures on rat control were widely distributed; displays were presented at local fairs, picnics and rodeos; and talks were presented to schools, 4-H clubs, agricultural societies, Chambers of Commerce and to just about anyone who would listen.
...let alone with this level of dedication from the educators:
> At a series of meetings with members of Indigenous communities, an Alberta Agriculture staff member ate warfarin-treated rolled oats while discussing rat control and the physiological effects of warfarin. He was able to effectively demonstrate the relative safety of warfarin to concerned community members, and they were able to move forward together.
It took about a decade for the program to work, but it did work:
> The number of known rat infestations in the border area increased rapidly from one in 1950 to 573 in 1955, and the numbers varied between 394 and 637 during 1956 to 1959. After 1959, the numbers of infestations dropped dramatically (Figure 3 [showing # rat infestations in Alberta hovering between 0 and 4 since 2000]). Hence, almost 10 years passed before an accumulation of training, experience and public education brought the rat problem firmly in hand.
And finally, rat control seems to be a point of genuine public pride. Something about regularly trumpeting government success in media is weird to me, but they seem to have earned it, and it's useful to keep people appreciative and aware.
> The discovery of a rat in Edmonton or Calgary receives full media coverage. In addition, the success of the program is reported by provincial or national media three or four times a year, and this success serves as a reminder to the residents that rat control is still an important program in Alberta.
Great link!
>>If not, can we release a rat specific poison or is that impossible without harming the entire ecosystem?
Animals bunch around places where there is food. And the hard part is if you have food these animals generally multiply well enough to eat that food.
In India its common to see street dogs, because food littering. Some times they take away the dogs, but they repopulate again in months/years. And in places where they don't litter you will see there are no dogs.
Animals bunch around places where there is food. And the hard part is if you have food these animals generally multiply well enough to eat that food.
In India its common to see street dogs, because food littering. Some times they take away the dogs, but they repopulate again in months/years. And in places where they don't litter you will see there are no dogs.
The way to get rid of rats is not poison, it's to remove their food sources. The only reason they live in the sewer system is that there's always something there for a rat to eat. The whole sewer system we use will have to be redesigned. Not impossible, but definitely not easy.
This reminds me of the saying "You're never more than 6 feet from a rat"
https://www.bbc.com/news/magazine-20716625
https://www.bbc.com/news/magazine-20716625
I was sat in my car at a motorway service station late at night recently and the place was overrun with rats. If people knew what was running around under their cars I'm sure they wouldn't have got out of them.
Neat article, for those looking to save a click:
"Urban areas in the UK cover around 16,000 square kilometres. If we distribute the rats evenly across the urban areas, which is clearly unlikely but necessary for the calculation, each rat has a rather spacious 5,000 square metres to roam around in.
Assuming you're standing at a given spot in an urban area you would be at most 164ft (50m) away."
"Urban areas in the UK cover around 16,000 square kilometres. If we distribute the rats evenly across the urban areas, which is clearly unlikely but necessary for the calculation, each rat has a rather spacious 5,000 square metres to roam around in.
Assuming you're standing at a given spot in an urban area you would be at most 164ft (50m) away."
"Assuming you're standing at a given spot in an urban area you would be at most 164ft (50m) away."
Not sure how they maintain a population if they remain 100m away from each other
Not sure how they maintain a population if they remain 100m away from each other
At most not at least
nandshab(2)
Leaving aside the pest aspect (and I'm sure it's all too real in many places), rats are fascinating creatures with a sharp, pragmatic intelligence, loads of adaptability, and social behaviors that we primates can very easily recognize and relate to.
I have seen rats perform clearly abstact thinking, brewing up complex ad-hoc plans, and show stunning degrees of spatial awareness. I have been lied to by a rat, who seemed to have worked out a decent model of my expected behavior. Which I promptly delivered - the rat won.
And these were domesticated rats. I should be surprised if their wild cousins weren't up to even more hardcore mental trickery.
> I have been lied to by a rat
...elaborate?
...elaborate?
Rat teaches me to feed her when she tattles her tray. But I won't do it until everything's been eaten, also the boring bits.
Then suddenly for weeks no trouble whatsoever - when she rattles her tray, it's empty, everything gone.
Until one night, hidden behind a doorpost, I watch her methodically clean out the boring bits and bury them under floor pellets. As soon as the tray is empty - rattle rattle rattle.
This was a supremely gifted individual. She performed similar strategems towars her cage-mates, for the most part successfully.
Oh, and I always wondered what all the fuss was about with the Japanese macaque monkeys and their cultural transmission stunt. I saw one rat getting inventive with the drinking water tap, beginning to take water with cupped paws and use it for washing her fur. Others picked up on that habit, and yes, it spanned generations.
Oh, and I always wondered what all the fuss was about with the Japanese macaque monkeys and their cultural transmission stunt. I saw one rat getting inventive with the drinking water tap, beginning to take water with cupped paws and use it for washing her fur. Others picked up on that habit, and yes, it spanned generations.
> Others picked up on that habit, and yes, it spanned generations.
It's memes (in the evolutionary sense) all the way down.
It's memes (in the evolutionary sense) all the way down.
How do you know it's deceit? It seems like you could get similar behavior if you filled two trays, one with food and the other with trash, and never provided food unless the trash tray was empty. You're training the rat to empty the tray.
It didn't just empty the tray. It hid the food. That does imply it took an extra step based on a mental model of the situation.
Not quite. She realised I could be tricked, but only if she thorougly covered her traces. I watched the thing. It was so clearly reasoned behavior.
200k doesn't seem like that much. Rats aren't very big, and Barcelona is a pretty large city, with a population of about 1.5M humans. I would have expected more, having grown up in a rural area where there's a lot more mice, rats and other critters than one per 7 humans.
A city’s aewers are tiny relative the city’s area. Parks, Apartments, etc are all going to increase the city’s rodent population.
Yeah, that number seemed low to me as well. I always assumed there would be more rodents in a city than humans. Odd to see that there are a million more humans than rodents in barcelona.
This is interesting, but is it really Hacker News-y? Regardless, thanks for sharing :)
Of course it is! 'Interesting' is the key criterion.
https://news.ycombinator.com/newsguidelines.html
https://news.ycombinator.com/newsguidelines.html
I initially saw the headline as "rats in Barcelona's servers" due to knowing what website I was on.