Media Study: Mouse City

if there’s so many of us why are we so alone?

Quick note before we get into it: this is a blog post, not a journal article. I’m keeping the jargon (and the research-method rabbit holes) to a minimum on purpose. I self-assigned this topic because the story is too fascinating to leave alone; yes, it might be a little rough around the edges.

I love an info dump. I love sitting down and saying: this is the niche topic I’ve been obsessed with this week.

And I’ve absolutely brought up the internet glory hole that is the concept of “Mouse City” in regular conversation and made myself sound deranged, so: fair warning. This is just a blog. It’s okay if I’m talking too much.

You might have heard of “Mouse City” (also “Mouse Utopia” / “Rat Utopia”) because it’s become a copypasta in some corners of the internet. The actual story being referenced in this game of telephone is Universe 25, a set of experiments by researcher John B. Calhoun. The short version people pass around goes like this: a population of mice is given food, water, and shelter in a controlled enclosure. As the population grows, the colony’s social order breaks down, and some mice withdraw into obsessive self-maintenance.

It gets retold as a parable about overcrowding, cities, or “human nature.” But the experiment wasn’t a city. It was a box.

So here’s what I’m actually doing in this post: I’m going to explain what Universe 25 actually was, and why the way it gets retold can be misleading.

And yes, there’s something to be gained from the experiment itself: population density has been a topic for years, and there are always more and more people, so we find ourselves more and more paranoid about collapse. What if we make the walls so high they cave in on us? What if, once trapped, all people are doomed to rot and fester and eat each other alive?

But people, in my opinion, don’t “go bad” like forgotten fruit. They adapt.

When faced with the worst, and pushed to emotional capacity, people withdraw into their homelands, their ethnic groups, their social class, and their studio apartments.

Shrinking your world can be a rational response to an environment that overwhelms you past a point of duress. The world can be big and oppressive to the senses, and sometimes we hide from that like mice in corners.

But no matter how tempting it is to compare ourselves to rodents, to personify the little creatures, and to assign all of the bullshit to them, we have to remember: mice have nowhere to go.

This is also why the story sticks. Mice are easy to personify. It is easy to picture a little mouse city, with a city hall, and a fair trade coffee shop where they union organize, and to feel that gut-punch of, wow, what if these mice were people. But they are not people. They are mice; they still did not deserve to be left in a box to breed to death.

I care about Universe 25 because it is not a city story; it is a closed-system story, and that difference changes what we can responsibly borrow from it.

Universe 25, explained

What Universe 25 actually was (the experiment, not the meme)

Universe 25 was Calhoun’s most famous “utopia” setup: a closed environment where mice had food, water, nesting material, and no predators; it also had no way to leave or reorganize once social life started getting weird.

The part that matters to me isn’t “utopia.” It’s closed system.

And Calhoun wasn’t shy about the human projection. One of the most-quoted lines from this era is:

“I shall largely speak of mice, but my thoughts are on man.” (Kean)

From there, the story people repeat online tends to flatten into: too many mice + too much comfort = collapse. But the actual detail is messier and more specific.

What changed as the colony grew (in rough order)

Here are the patterns that matter, in the order I think they unfold.

1) Clustering first (not isolation). This is the part that gets lost in the “they isolated” retellings: at the beginning, they weren’t isolating; they were clustering.

They were piling into the same spaces to eat and socialize, and that clustering becomes the pressure point.

Calhoun describes what he called a behavioral sink as a learned, self-reinforcing bottleneck:

“Development of such pathological aggregations led to the formulation of the concept of ‘behavioral sinks.’” (Calhoun, “A Behavioral Sink”)

2) Care collapse (not resource collapse). Distillations summarizes the later-stage pattern bluntly:

“... leaving the pups to die of neglect.” (Kean)

This is the direct correlation that gets buried in the “utopia” retellings: the colony didn’t fail because it ran out of food. It failed because social stress led to mice that were procreating but unable to care for themselves or the pups.

Calhoun’s earlier density work makes the same point in a way I find clarifying: resources weren’t the limiter; stress was.

“With an abundance of food and places to live and with predation and disease eliminated or minimized, only the animals’ behavior with respect to one another remained… There could be no escape from the behavioral consequences of rising population density… The reason this larger population did not materialize was that infant mortality was extremely high… stress from social interaction led to such disruption of maternal behavior that few young survived.” (Calhoun, Population Density and Social Pathology)

So yes: these mothers weren’t caring for their pups. The pups were being left to die.

Here’s me speculating, because this is a blog post and I’m allowed to wonder out loud: if you’re overstimulated, overwhelmed, and you don’t have a real way to process and decompress, it’s not hard to imagine how you lose the capacity to nest correctly, rest, and care for yourself through pregnancy; that loss then ripples straight into how you care for newborns. It’s almost like these were not ideal conditions for having a child, but because Calhoun wasn’t studying birth control, the mice multiplied.

And in later generations (and in later experiments), the mice would slowly stop procreating at all; maybe this was a response to realizing how not-ideal these conditions were. The female mice were separating themselves off by then. And some of the male mice were tweaking out from lack of girls in their area…

3) The “beautiful ones” (and the internet’s worst reading):

“Maladjusted males, meanwhile, took to grooming all day - preening and licking themselves hour after hour. Calhoun called them ‘the beautiful ones.’” (Kean)

This is the part that gets ripped to shreds online, because people hear about the over-groomed, stressed-out incel mice and it’s “look at that beta soyboy cuck,” which is… fucked up, you know?

But animals under stress do this exact kind of thing all the time. The behavior itself isn’t “decadence.” It’s a stress signal. (And yes, I also thought of the looksmaxxing guy.)

4) Withdrawal as a literal pattern.

“Among the males the behavior disturbances ranged from sexual deviation to cannibalism and from frenetic overactivity to a pathological withdrawal from which individuals would emerge to eat, drink and move about only when other members of the community were asleep.” (Calhoun, Population Density and Social Pathology)

And there it is, hades: so depraved and far gone they don’t even gnaw on each other anymore; they just hide. Sneaking out in silent moments to avoid contact with another living soul. If these rats had contactless pay, they could avoid each other forever.

The part people flatten into a meme

The oversimplified version is: “the mice got comfortable, then bored, got weird, and collapsed.” The real version is: a social animal got trapped in a closed system, and the stress rewired the whole group; Universe 25 does not prove “cities make people evil,” but it does show how behavior changes when an environment makes social life feel unsafe and inescapable.

And it keeps resurfacing because it’s a clean story with a creepy image, so people reuse it to argue about whatever they already believe about modern life, while the most important detail stays the same: the mice couldn’t leave.

You can cash in this internet gold nugget to argue the harms of overpopulation, the terror of unfit and ill equipped poor mothers, the moral collapse of everyone wanting to party and fuck and snort drugs at Coachella, or you can witness tha animal cruelty for what it is and not center the human experience in this very real torture that happened to another being on earth.

Closing note

What haunts me about Universe 25 is not the “collapse” story people love to retell; it is the scope of the enclosure. A social animal is put into a system with no exit, no privacy, constant stimulation, and stress intense enough to scramble status, territory, and care.

In that kind of pressure cooker, yes, even people would probably snap at each other. That is not a moral failing; it is a predictable response to an environment that removes relief and concentrates stress.

The useful question, then, is not “are cities evil,” but “what makes a city livable.” Where are the quiet places, the buffers, the exits, the third spaces, and the systems that keep power from collapsing into a few choke points. Universe 25 is not a prophecy; it is a warning label for design, and a reminder that we can build cities, and lives, that work better than a box.

Sources / further reading

If you want to go down the rabbit hole:

Call to action

If this hit a nerve, do not try to “fix yourself” tonight. Pick one small, concrete, pro-connection move to try this week; something your nervous system can tolerate.

If you want to share: what is your version of a bottleneck right now (the narrow gate where life starts to feel unlivable), and what kind of connection actually helps?

Also, would you read a post about hikikomori? Would you have advice for one?

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