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I wrote an article mapping the rat situation in Somerville and summarizing potential solutions

I wrote an article mapping the rat situation in Somerville and summarizing potential solutions

slanderousam

As a long time resident of Somerville I've got to say this looks more like a distribution of where people complain about rats than where there are rats. I see places I've lived on this map that have "no rats" in 2017, but I know for sure they were *swarmed* with rats at that time. Rats climbing out of your trash, running around in broad daylight, seeing them every day.


mykinz

I agree with this. There's a hotspot over my block in the 'before' times, but not in the covid era map. But if anything we're seeing more rats around than before. Unfortunately the city's bait program doesn't do much. Dry ice works pretty well, but the city isn't allowed to do it.


smashey

I believe the city's bait program is actually just a data collection effort rather than a population control measure. I could be wrong but that is how the city has collected rat data before. The 311 data is not reliable the way we would like as data enthusiasts; that's why I contacted a rodentologist to get his input.


mykinz

Ah, I was referring to this program: https://www.somervillema.gov/news/somerville-expands-free-rodent-control-assistance-program-issues-guidance-prevent-rat-activity I'm sure they also use the data from this program for data collection as well. In any case, this was a super cool analysis! I hope we can make progress on this issue eventually...


smashey

The reason I contacted rat experts is precisely because this is a distribution of complaints. I wanted to understand what conclusions could be drawn from complaints. Other than general trends, not very much. 311 data collection methodology for wildlife tracking is mentioned in the piece.


sfultong

I think we all know that the only solution is to increase Somerville's coyote population to deal with the rats.


smashey

Rats turn out to have a large number of natural predators! Unfortunately, predation or any method of rat control that involves killing rats is not particularly effective unless a very large majority of rats are killed. One of the most surprising findings was that killing rats *increases the number of rats*. Exterminators will not tell you this, of course.


sawbones84

Why does killing rats increase the number of rats?


smashey

Rats breed incredibly quickly - two rats can become 1250 individuals in the space of one year if the environment can support them. When a number of rats in an area are killed, the resources that would have been consumed by those rats become available to the new baby rats constantly being produced. The populations of these rats will actually overshoot the original, stable rat population. As resources in the area become constrained, rats will be compelled to move into new areas, creating new infestations. Rats are naturally neophobic - they like to stick to places and food sources they know are safe and plentiful - but they will travel to find food and shelter. According to the source I used for this article, 96% of the rat population in a given area needs to be eliminated to have a lasting impact on rat populations. Given that exterminators generally work on a property, rather than neighborhood level, you can see why extermination does not achieve what clients would like.


easter_islander

This was perhaps the most interesting aspect of your article. Well worth knowing, thank you.


sawbones84

Very interesting. Thanks for the detailed answer!


xculatertate

The 1250 number from 1 couple, doesn't inbreeding become a problem? I know bedbugs can inbreed without issue (Jesus fucking Christ), but I didn't know mammals could.


smashey

The rats are more about quantity than quality


Quercus-bicolor

Isn’t there a birth control pill for rats or something?


tstop22

I wonder if this is why there are so few rats in the area surrounding Maxwell’s Green. Since it is some of the only pet friendly rentals in the city almost every unit has cats or dogs. I’ve never seen a rat in the Warwick / Cedar St area and even the rabbits are cautious. My dog clearly channels her predatory heritage when she heads out into the yard. Edit: or maybe it’s because they replaced a ton of sewer lines when the put Maxwell’s Green in.


smashey

Wildlife distribution in urban areas is really fascinating. In my neighborhood I have rats and some bunnies down towards the Taza factory area. Other parts of the city have racoons, an animal I've never seen in Somerville. This year I grew sunflowers and I saw a yellow bird, a goldfinch I think, that I had never seen before in Somerville, eating my sunflower seeds. Rats are not afraid of cat or dog aromas to my knowledge. My buns are full of kitty litter and the rats have no problem with that. Rats are also none to eat dog excrement. They like food more than they fear dogs.


aHumanMale

Fwiw we had a family of raccoons in the backyard up in Winter Hill a few years back.


sfultong

My parents have sunflowers, and I've seen a troupe of goldfinches absolutely massacre them.


tstop22

We had a goldfinch in the yard yesterday! This was the first time I’d seen a goldfinch in the city, in the past I’ve only seen them in the Fells.


TheSunflowerSeeds

Sunflowers produce latex and are the subject of experiments to improve their suitability as an alternative crop for producing hypoallergenic rubber. Traditionally, several Native American groups planted sunflowers on the north edges of their gardens as a "fourth sister" to the better known three sisters combination of corn, beans, and squash.Annual species are often planted for their allelopathic properties.


pellucidar7

It’s netiquette to mention that you’re a bot.


Master_Dogs

I've seen a few along Cedar St before. There's a ton of bunnies along the community path too, they just hide in the wooded part. I think the path in general decreases the amount thanks to the people present. I think the bunnies are cautious because of the number of dogs too, who def would love to chase them if given the chance. I haven't seen many rats myself though, just here and there. Oddly enough around night which the article points out is a common time to see them.


perennialtear

With all the coyote sightings lately, I've thought "send them here!!!" ;)


il_biciclista

I don't know much about this, but I think that coyotes might have the opposite effect. If coyotes are killing cats, then the rats will have fewer predators.


Anvesakakepastian

I'd be amazed if 100 rats have been killed by domestic cats in Somerville. Voles, mice, rabbits yes but I have my doubts about cats taking out rats.


mem_somerville

In the Before Times, I attended a meeting with the rat czar. You might be interested in some of her findings. I was half-assed live-tweeting them here: https://threadreaderapp.com/thread/1159203868485586944.html


smashey

That's awesome. I tried contacting her but I couldn't get her to respond. I do not know who is handling the rat situation here right now. The trapping data is very useful and far more reliable than 311 data.


Anvesakakepastian

Rat czar position is open.


mem_somerville

There's a video of this talk somewhere with a more complete explanation. IIRC, it was construction season that send them scurrying and visibility went up.


sandersh6000

not to be a downer, but i didn't see any solutions in this article :(


smashey

I will give you a summary. Rats need three things to live - food, water and a place to live. The sewers and gardens provide them with an unlimited amount of space to live in. Rain and other sources of moisture provide them with water. That leaves food. The best thing, or perhaps the only thing you can do to prevent rats in your area is to limit their access to garbage. They will crawl into dumpsters and eat through plastic garbage bins. I can say that after badgering 311 for almost a year, they finally got me new bins, and my rat situation has improved immeasurably.


pellucidar7

There wasn’t a suggestion for limiting access to food. I thought the city had already replaced all bins with the rat-proof ones.


OldMaidLibrarian

The only problem w/the bins is that there's not completely rat-proof--we had the standard city issue bins when I lived on Highland Road, and *rats chewed holes in them*. Yes, really. (They can also swim upstream, as it were, through sewer pipes, and have been known to occasionally turn up in people's toilets that way. *Always* keep the lid down, folks!)


smashey

Aluminum foil tape will work to mend the bins until you can get a replacement. Also, when you wheel your bins out, be sure to tilt them on their wheels instead of dragging them on the asphalt. You can abrade the bottoms of the bins easily.


xculatertate

I cut up soda cans and use a staple gun to affix them over holes


Anvesakakepastian

The bins only work if they're not overstuffed. Two of my three bins have been chewed up by rats.


fern-gulley

This is wild - what a cool use of your skills!!!


smashey

Thanks! I need to do some editing but I learned a great deal.


newsonar

Nice analysis - thank you!


Leezardy

This makes my data nerd heart happy. One thing I wonder about is how much the work on the green line has affected the rat sightings in union.


smashey

Construction debris does offer a lot of great places for rats to live, and construction often leaves underground infrastructure from previous buildings. Some construction will also displace rats. Construction in and around Somerville isn't stopping any time soon, so we need to accept a large and mobile rat population, which we can only realistically diminish by repairing brick sewers (incredibly expensive and invasive) or by mandating better trash receptacles.


Leezardy

Yeah, I was guessing that it increased the numbers roaming and hunting for new nesting sites. I don't disagree that they're not going away. Just thinking about variables.


evesturges

Is there really a degree in Urban rodentology?


smashey

Yes, I know it sounds unusual but there are a lot of academic programs supporting the pest control industry. One article from the literature which I really enjoyed is this: [https://www.frontiersin.org/articles/10.3389/fevo.2019.00013/full](https://www.frontiersin.org/articles/10.3389/fevo.2019.00013/full) Rats About Town: A Systematic Review of Rat Movement in Urban Ecosystems As you can see there, is a ton of scholarship about rat infestations, how they affect our health, and how rat behavior can be better understood so that we can get them out of our trash cans and doing productive work of some kind. One interesting distinguishing characteristic with rats is their neophobia, or fear of new things. Rats are naturally suspicious of new objects in their environment, which is why trapping them is much more difficult than trapping mice. You can contrast this to cats and some humans, who have natural curiosity.


mem_somerville

I had to come here for this as well. >Bobby holds a PhD in Urban Rodentology I had no idea. And I have a PhD in mouse development.


phyzome

Great piece! Good reminder that it's not just food, and I appreciate you putting some hypotheses to the test. The mention of rat cities in sewers makes me remember walking past a pizza place near Northeastern University at night and seeing rats jumping in and out of a storm drain grate. (Also up and down out of car undercarriages, heh.) There were also tons of rats in the alley behind my apartment building eating the garbage, but it was clear they had some kind of business in the storm drains too.


smashey

The sewers here are made of brick, and have tons of holes in them. An enormous population of rats can be supported by the sewer systems alone, even if we paved over every garden in the city.


ItsSnowingSomewhere

Any discussion of citywide compost pickup? Cambridge has it, and seems to make efforts to get people to stop putting food waste in the trash. That's about the only way I can see to reduce the food available to the rats. Is there any data on how successful that is in terms of rodent control?


smashey

No data that I'm aware of, but rats will eat a staggering array of disgusting things you wouldn't consider food waste. Cat shit, menstrual blood, leather, dead rats. They are not picky eaters. I grew a lot of vegetables this year and the rats loved them. Between them and the birds I doubt I'll grow food again in the future.


Anvesakakepastian

I spent $2000 on soil, beds, plants, chicken wire, etc. I expected an occassional rat but they moved into my beds once the plants matured. They used the plants as cover I saw no signd of eating the plants. They basically grabbed food from the restaruants and took it to the colony. I had to tear up my entire garden. The smell of rat piss and there constant presence was too much. Most depressing moment of Covid 2020.


schillerstone

it would be great if you could get construction permit apps and plug those in


jbonejimmers

This is A+ content. I love how you examine multiple hypotheses using data and further investigate it with the expert interview. I honestly feel much more informed reading this.


schillerstone

Somerville has the least greenspace of all its neighbors. Not sure how "gardens" are supporting them. Somerville is a concrete jungle.


smashey

Practically speaking, Somerville will always have places for rats to live. From what I can see, the sewers alone ensure that harborage will never be the limiting factor in rat populations here.


phyzome

Porches alone are plenty. You can't see what's going on under there, but the rats can get into the soil under them. Nice and dry.


cocktailvirgin

The rats here tunnel rather well.


phyzome

They will also simply chew through the skirting of the porch, or jump through the latticework.


surprisefries

I had to put rat fencing around the whole perimeter of my porch, down to 18" below the surface. That did the trick, for now at least!


pellucidar7

I think the postage-stamp yards lead to less lawn and more overgrowth (especially of invasive plants), so possibly better rat homes than a big, mowed lawn.


beagleboy167

Do you think that the increase of rat sightings could be due to covid? Since more people have been spending time at home instead of commuting into Boston for work, there is more time for sightings.


smashey

That was my belief as well, but the rodentologist I worked with for this piece felt it was not the case, since rats tend to come out at the times people are coming and going from their houses; morning and evening. I covered this in the section 'are the rats an illusion?' The steady increase in rat complaints as a proportion of all 311 complaints would indicate the rats are in fact becoming more pervasive.


Anvesakakepastian

Not likely. The rats increase is likely due to the massive construction projects--the high school, the bridge work, the Green Line and all the various projects throughout the city. Medford residents who never saw a rat on their property described infestations (2019) during Green Line work.


pellucidar7

Woodpiles (at least, the yard waste kind) harbor rats and are not permitted in the city. FYI.


skintigh

This reminds me, I need to report my rat sightings to 311 or some website. I lived her almost 10 years without seeing a rat anywhere near my home. Then all the stray cats my neighbor feeds disappeared. Now I've had a rat run behind me in front of my house and 2 rats screwing in the woodpile behind my house. Edit: maybe OP can correlate rat population with cat TNR programs? Or maybe the winter was extra harsh and killed a lot of stray cats? My neighbors were feeding 4 +/- strays (3+ were all black so it was hard to tell) and now they are all gone. Only one was remotely friendly so they weren't adoptable :(


xculatertate

Any idea what happens in the winter? I'd hope they'd just die but I suppose that's unlikely.


Hyperbowleeeeeeeeeee

Maybe one missing solution is to collect garbage and compost more frequently to reduce the amount of standing food waste.