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A scientist created a 'utopia' for mice and then they all started dying

The results are fascinating, but are they relevant to humanity?

Canva Photos

How could Mouse Heaven go so terribly wrong?

In 1968 John Calhoun, a scientist and animal behavioralist, decided to create a "utopia" for mice. It would have unlimited food and water, with beautiful nesting spaces and plenty of materials for the mice to make cozy homes with. Sweet experiment! the mice were probably thinking. Much better than the Maybelline trials we're used to.

However, there was a catch, of course. There was one thing the utopia would be lacking, and that would be physical space. As the mouse population grew, overcrowding would become an issue, and Calhoun wanted to study the problems this would potentially cause. That sound you hear is the collective sigh of the disappointed mice who were stoked about the 24/7 all-you-can-eat buffet.

The experiment, dubbed Universe 25, began when Calhoun introduced four mouse "couples" into the utopian complex. A year or so later, it was overrun and the conditions had turned hellish, even though the mice had not run out of food or water.

mouse, mice, animals, science, research, studies"The conditions had turned WHAT?"Giphy

Initially, for just the eight original mice, the square box Calhoun built included 256 nesting boxes (or apartments) stacked on top of one another. Water bottles and food dispensers were located all along the nesting spots, and mice could travel throughout the complex at will via mesh tunnels. The starter mice were also screened for diseases and the population was obviously protected from predators. The climate was controlled and comfortable. Conditions were perfect.

The first mouse pups showed up a little over three months later, with the population of the colony doubling every 55 days. Nineteen months later, there were 2200 mice living inside the box. With such perfect surroundings, the infant mortality rate was practically zero, leading to the rapid rise in numbers.

mice, mouse experiments, scientific research, animal experiments, overpopulationJohn Calhoun poses with his rodents inside the mouse utopia.Yoichi R Okamoto, Public Domain


By month 19, this rodent utopia had become an overcrowded hellscape. Calhoun noticed three alarming trends, in particular.

In short, everything was devolving into chaos and the very society of the mice began to collapse at a rapid rate.

The "Beautiful Ones" and the "Dropouts": Mice have a complex social hierarchy ruled by dominant alpha males. Sam Kean of Science History Institute Museum & Library notes that, in the wild, non-dominant males (the ones who lose macho showdowns) can skip town and start over somewhere else. But in the close quarters of Calhoun's experiment, with nowhere to hide, they were forced to hang around and viciously battle with each other over scraps. Eventually, non-dominant male mice, which Calhoun called the "Beautiful Ones," withdrew from society completely and only ate, slept, and groomed themselves.

Though resources were unlimited, certain aggressive males hoarded them anyway: The alpha males ruled over everything in the once-utopian mouse society. They kept harems of females in the apartments to mate with and fought fiercely to defend their territory. But new waves of hungry young male mice kept coming and coming, and eventually even the most dominant alphas abandoned their posts. This led to more attacks on nursing females, which in turn led to more mothers kicking their pups out of the nest early.

Birth rate declined dramatically: With the non-dominant males giving up completely and focusing on #SelfCare, dominant males too exhausted from endless battles, and females sick and tired of it all (many became asexual hermits by the end), stopped mating and giving birth entirely. Once this happened, the society was doomed. Even with plenty of food still available, cannibalism was rampant.

Calhoun was not shy about drawing parallels between his research and humanity. "I shall largely speak of mice, but my thoughts are on man, on healing, on life and its evolution," he once wrote.


mice, mouse experiments, scientific studies, universe 25, sociology, overpopulationAlpha male mice, anyone? Photo by Kanashi on Unsplash

There are aspects of his wild experiment that certainly sound familiar.

We live in a world with plenty of resources for everyone, but a few select people hoard more than their fair share. When you think of the rodent "apartments," it's hard not to picture densely packed urban environments where people are stacked on top of each other at every turn. Maybe on some level some of us can relate to the “Beautiful Ones” and their urge to not participate in all the ugliness and just sequester and groom themselves. You can make an argument that when the mice stopped having to worry about food and shelter, it removed the element of challenge from their lives and left them lost–like many of us are lucky enough to not have to wonder where our next meal comes from, and maybe that has something to do with our never-ending search for meaning. Some even go so far as to link more people choosing to delay having children, or not have children at all, with the collapsing society of the mice.

But Calhoun's work has also been heavily scrutinized, with some claiming it's based on shaky science. And in the end, there’s the small matter that humans are not mice. We are infinitely more complicated, and so much better suited to adapting to our environments. Kean writes, "Ultimately Calhoun’s work functions like a Rorschach blot—people see what they want to see."

It's fascinating and thought-provoking nonetheless.

Three teenage girls enjoying some cake.

Have you ever felt like you can hardly stand after having a big dinner at a restaurant, but when the dessert menu is dropped on the table, your stomach miraculously finds a way to accommodate another 800 calories of cheesecake? Does that mean you weren’t completely full, or your stomach can always find room for dessert? According to a recent study out of Germany, we’re programmed to find room for dessert, even when legitimately full.

The Max Planck Institute for Metabolism Research, led by Henning Fenselau, PhD, performed a study on mice after being confused by what they call “dessert stomach” or the strange way we have an appetite for sugary foods when we have zero interest in another bite of our dinner. The researchers found that after eating a meal, a paradoxical thing happens: the same neurons that trigger us to feel satisfied also create a desire for sugary foods simultaneously.

cake, eating cake, appetite, scientific studyA couple enjoying some cheesecake.via Canva/Photos

To understand why this surprising effect happens with our appetites, the researchers gathered a hungry group of mice and fed them chow for 90 minutes. After the mice were satisfied, the scientists offered them another 30-minute period where they were given more chow or a substance high in sugar. The mice given a second helping of chow would take a little nibble, but if they were given a meal high in sugar, they would increase their caloric intake sixfold. For humans, this is like enjoying a filling club sandwich with soup and salad, then knocking back a nine-scoop sundae with whipped cream, nuts, and a cherry. “This vigorous stimulation of consumption of the high sugar–containing food was consistent across all mice,” the researchers wrote.


Is dessert stomach real?

The secret to “dessert stomach” lies in a group of nerve cells called pro-opiomelanocortin (POMC). When the mice were full of chow, these neurons fired off signals that they were satiated. At the same time, it also triggers the release of ß-endorphin, one of the body’s opiates that creates a feeling of reward that causes the mice to continue to consume sugar even after they are full.

It’s also worth noting that the opiate was released in mice that had never even tasted sugar before, showing they are hard-wired to consume sugar every chance they get. “From an evolutionary perspective, this makes sense: sugar is rare in nature but provides quick energy,” Fenselau said. “The brain is programmed to control the intake of sugar whenever it is available.”


Scientists believe humans have a strong drive to consume sugar because its energy allows them to stave off starvation, giving them a greater chance to reproduce. However, fruit is often found high up in trees, so the primates would need a strong drive to climb the tree to get it. The amount of sugar provided by these fruits was relatively small, so there were no adverse health impacts from eating whatever sugar they could get their hands on. But in 2025, at a time when sugar is plentiful, this drive is a big reason for the obesity epidemic in developed countries.

The good news about the study is that the next time you eat a big meal and still crave a hunk of cake even after you are full, it’s not because you prioritized dessert over your nutritious meal. It’s because, over thousands of years of evolution, your mind has found a way to trick you into eating all the sugar you can, even when you don’t have any space left for anything else.

Popular

Neil deGrasse Tyson posted a gym selfie in a muscle shirt and people  are loving it

"A physicist thirst trap is the pleasant surprise I didn't know I needed."

Neil deGrasse Tyson in a visit to NASA

For most of us, National Pi Day (March 14th, of course) came and went without much fanfare. Maybe a few show-offs recited the famous 3.14 number to as many decimals as they could remember, or someone whipped up a blueberry pie in a punny homage. But if you happened to open Facebook and follow astrophysicist Neil deGrasse Tyson, you were in for a unique surprise.

First, some might ask: what is pi? In the piece, "What is Pi, and How Did it Originate" by Steven Bogart for Scientific American, he explains, "Succinctly, pi—which is written as the Greek letter for p, or π—is the ratio of the circumference of any circle to the diameter of that circle. Regardless of the circle's size, this ratio will always equal pi. In decimal form, the value of pi is approximately 3.14."


Pie Pi Day GIF by PusheenGiphy

Here's Neil on TikTok with a cute video in anticipation of Pi Day. In its description, he writes, "We're just a few days away from #PiDay. Here's a friendly reminder to share with your friends along with a few jokes to use this year:

Why should you never start talking to pi at a party? Because it just goes on forever. What did pi say to its sweetheart? You look radian today. What was Sir Isaac Newton’s favorite dessert? Apple pi."

@neildegrassetyson

We're just a few days away from #PiDay 🤓 Here's a friendly reminder to share with your friends along with a few jokes to use this year: 🥧 Why should you never start talking to pi at a party? Because it just goes on forever. What did pi say to its sweetheart? You look radian today. What was Sir Isaac Newton’s favorite dessert? Apple pi.


Over on Facebook on March 13th, he shared a photo of the moon, and in a separate post, a little more information and some fun recommendations about Pi. "Pi Day (3.14) Pi has a few more digits than that. But 3.14 can get you far. Wanna get your geek on? Celebrate at 1:59:26. That gets you 3.14 1:59:26, the first seven decimal places of Pi."

The next morning, around dawn Pacific Standard Time, Neil changed his profile picture to one in which he's wearing a sleeveless muscle shirt, standing in front of a mirror at what appears to be a gym. Yes, Neil gave us a gym selfie, and why wouldn’t he?

selfie gym GIFGiphy

His followers seemed delighted, with the comments reflecting a balanced mix of good humor and earnest compliments. In one of the top comments, someone wrote, "A physicist thirst trap is the pleasant surprise I didn’t know I needed. You’re in fine form, sir." Yet another seemed (jokingly) threatened: "Damn bro, save some science for the rest of us."

This person disagreed that Neil was seeking validation: "I don't know why, but I just cannot make myself see this as a thirst trap. I know you weren't even meaning it in a bad way, but he is just so humble that anything like this just somehow makes him more human and accessible. Like he's having a confident day and wants to commemorate it."

A few people really honed in on how toned his muscles are. "Neil DeGuns Tyson," one person exclaimed, while another wrote, "Don't forget, he was a high school wrestler. The muscle never completely goes away."

Neil Degrasse Tyson Whatever GIFGiphy

This commenter was perhaps referring to Neil's propensity to debate: "Feelin' cute. May agitate some astrologers later. Idk."

And lastly, this person was hopeful that the photo is the start of a training montage: "Please tell us you're training for Cosmos Season 3.... we need this!"

Innovation

7 mindblowing medical breakthroughs that could occur in our lifetime

One day soon, you might be able to grow new teeth. Seriously.

Canva Photos

My family has a history of Parkinson's Disease, so I always see the headlines that promise some major scientific breakthrough in regards to the disease based on small, lab-based experiments or trials run on animals. They give us a glimmer of hope but, far too often, these treatments never see the light of day. The road from promising idea to having a real treatment available for patients is extremely long and arduous. Most potential new medications and therapies don't survive.

But... things do sometimes happen! There are massive medical breakthroughs being achieved all the time. Sometimes it's a new discovery, sometimes it's a successful clinical trial, and sometimes it's the fruit of all that labor finally becoming publicly available to people who need it the most. For example, an RSV vaccine just became available in 2023 for the first time. A powerful non-opioid pain killer was approved in 2024. A new drug came out to treat schizophrenia that was completely different than anything that had come before. Progress is being made every single year.

In our lifetime, say the next five to 20 years, we could see unbelievable advancements in treating certain medical conditions. Here are a few pretty amazing potential developments that are on the horizon.

Scientist working in a laboratory setting. Photo by Adam Bezer on Unsplash

1. Growing new teeth

Unlike sharks, humans are known to grow only two sets of teeth, our baby teeth and permanent adult teeth. If one gets knocked out or lost due to decay or infection, you're out of luck!

But researchers say growth buds exist in our gums for a third set, and scientists in Japan have had success in activating them to grow naturally. It could be a major gamechanger that could one day replace dentures and prosthetics. The team has moved onto human trials and has a target date of having a drug ready by 2030.

2. Cancer vaccines

Medical scientists have made amazing strides in cancer research, especially in the field of vaccines.

Did you know that lung cancer is considered to be the most deadly of the bunch? A lung cancer vaccine could be available very soon. If a cancer vaccine sounds odd, think of it this way: Cancer can be treated by chemotherapy and radiation, but there's always a chance of it coming back. People who have survived cancer could theoretically take the vaccine and massively improve their chances of reoccurrence.

A similar vaccine is showing promising results in clinical trials for pancreatic cancer.

3. Better treatment for Alzheimers

Alzheimer's Disease is one of the most destructive and heartbreaking conditions imaginable. It's also extremely difficult to treat, with most currently available therapies and medications focusing on slowing or temporarily relieving certain symptoms.

One new avenue scientists are exploring is a vaccine that could target a protein called tau, which clumps together and tangles up crucial neurofibers that deliver information in the brain. One such medication aims to activate a patient's immune system and produce "a strong antibody response against both pTau and its harmful aggregated form." The drug was recently fast-tracked by the FDA and has shown promising results in human clinical trials.

Another relatively new development is the availability of monoclonal antibody treatment, which helps slow the progression of the disease. Currently, the treatments are not particularly cost-effective but may become moreso in the near future.


smiling woman in gray cardigan Photo by Tatiana Zanon on Unsplash

4. Breakthrough treatment for Huntington's Disease

Huntington's is a fatal central nervous system disorder that shuts down key brain functions in patients like speech, walking, and cognitive function. Some of the symptoms can be treated but, so far, little can be done to slow or stop the progression of the disease.

However, a new drug known as PTC518 was recently fast-tracked by the FDA due to promising results in clinical trials. It attacks mutant Huntington protein in blood cells and in cerebrospinal fluid and has been shown to improve symptoms of the disease in a 12-month trial run. What's especially exciting is that this drug attacks the disease itself rather than just treating symptoms at the surface level.

5. Targeted viruses that kill antibiotic-resistant bacteria

Bacteria is getting smarter and evolving. Antimicrobial resistance is a grave threat to the global population as well-known antibiotics become less effective against infection and new antibiotics are expensive and difficult to develop.

(If you've ever dealt with a staph infection, you know how scary it is when drugs just... don't work.)

This is where special viruses, called bacteriophages or just phages, come into play. These viruses selectively target and kill bacteria, and were actually first used about 100 years ago. Scientist are coming around to using them again. In select settings, they've proven to be incredibly effective against resistant infections, but will need more testing before they become widely available. However, it's definitely possible that this become a viable alternative to antibiotics in some cases in the next few decades!

6. Synthetic and bioprinted organs


human heart Photo by camilo jimenez on Unsplash

There are simply not enough donor organs going around for all the people who need a healthy liver, heart, or kidney.

Luckily, incredible strides have been made in creating artificial organs that can function like the real thing. A man in Australia just lived for 100 days with a titanium heart while he awaited a transplant! And bioprinting technology – quite literally 3D printing using real tissue and living cells — has the potential to create new working organs from scratch in the near future. Genetically modifying animal organs to function in humans temporarily or maybe even permanently has also come an extremely long way and is a process that will drastically improve in the coming years.

7. A one-pill cure for Hepatitis B

Hepatitis B is a potentially fatal infection of the liver that affects hundreds of millions of people worldwide. There is a safe and effective vaccine available to some people, but it's only preventative and won't treat active infections.

A research team in Israel recently discovered that a low dose of well-known chemotherapy drug, Curaxin-137, completely destroyed a crucial and mysterious protein that the Hepatitis virus depends on. The testing was done in a lab setting, so the next step is clinical trials. The team hopes that one day in the not-so-distant future, patients could take a single dose and completely eradicate the virus in their system. That's about as close to a miracle-cure as you can get!

Not all of these potential breakthroughs will come to fruition, but it's pretty amazing to dig into the advancements and discoveries that are being made every day. This list is just scratching the surface, to say nothing of robotic surgeons that will make major surgeries less invasive, new treatments for baldness, nanotechnologies that can deliver medicine to specific parts of the body, and more. Ultimately, good news is coming relatively soon for people who need it.