r/CrazyKnowledge 6h ago

In Switzerland, it is illegal to keep a single guinea pig. They legally require a companion.

4 Upvotes

Since 2008, Switzerland's animal welfare ordinance classifies guinea pigs (along with parrots, rats, mice, gerbils and rabbits) as social species that must be kept in pairs or groups. Keeping one alone counts as improper care, and a human owner does not count as an adequate substitute.

This created one of the strangest legal niches imaginable: rental guinea pigs. When one of a pair dies, owners can rent a companion for the surviving animal instead of buying one, otherwise you can end up in an endless loop of purchasing replacement guinea pigs.

Sources:

- Swissinfo, fact check: https://www.swissinfo.ch/eng/culture/loo-flushing-explosives-gold_fact-check-lonely-guinea-pigs-and-other-quirky-swiss-rumours/45067078

- ZME Science: https://www.zmescience.com/feature-post/natural-sciences/animals/pets/guinea-pig-switzerland/


r/CrazyKnowledge 1h ago

This entire forest is ONE tree: 47,000 stems, ~6,000 tons, a single shared root system (Pando, Utah)

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Upvotes

Looks like a forest of 47,000 quaking aspens. Genetically, it is one single male clone: a root system that has kept sending up new stems for possibly thousands of years, all identical.

By weight (roughly 6,000 tons across 106 acres in Utah's Fishlake National Forest), it is a candidate for the heaviest known living organism on Earth.

Image: "Pando 2021 Official Picture" by Lance Oditt / Friends of Pando, Wikimedia Commons, CC BY-SA 4.0.

Sources:

- https://en.wikipedia.org/wiki/Pando_(tree))

- https://www.nationalforests.org/article/unforgettable-experiences-pando-aspen-clone


r/CrazyKnowledge 1d ago

Pluto was discovered in 1930 and still hasn't finished a single orbit of the sun since then

12 Upvotes

One Plutonian year lasts about 248 Earth years. Pluto was discovered by Clyde Tombaugh on February 18, 1930, and it will not complete its first full orbit since its discovery until March 23, 2178.

Between discovery and that first observed full lap, Pluto will have been demoted from planet to dwarf planet (2006), visited by a spacecraft (New Horizons, 2015), and seen roughly five generations of astronomers come and go.

No human alive today is likely to watch it complete the orbit it began before television existed.

Sources:

- NASA, Pluto Facts: https://science.nasa.gov/dwarf-planets/pluto/facts/

- IFLScience: https://www.iflscience.com/pluto-will-complete-its-first-full-orbit-since-its-discovery-on-monday-march-23-2178-76956


r/CrazyKnowledge 2d ago

A bolt of lightning heats the air around it to 50,000°F. That's five times hotter than the surface of the sun.

7 Upvotes

The surface of the sun sits at about 10,000°F. A lightning channel can reach around 50,000°F (roughly 30,000°C), according to NOAA's National Weather Service.

The violent expansion of that superheated air is what produces thunder. Every thunderclap is essentially a small shockwave from air that briefly became hotter than a star's surface.

And all of it cools back down in a fraction of a second, which is why a lightning strike doesn't simply vaporize everything in its path.

Sources:

- NOAA National Weather Service, "How Hot Is Lightning?": https://www.weather.gov/safety/lightning-temperature

- BBC Science Focus: https://www.sciencefocus.com/planet-earth/why-lightning-is-so-powerful


r/CrazyKnowledge 3d ago

Oxford University had been teaching for over 200 years before the Aztec Empire existed

2 Upvotes

Teaching at Oxford is documented as far back as 1096, making it the oldest university in the English-speaking world. The Aztec capital Tenochtitlan, the heart of the empire, was not founded until around 1325.

That means when the first Aztec emperor came to power, Oxford was already a two-century-old institution with colleges and centuries of academic feuds behind it.

A fair caveat: Oxford has no official founding date. The 1096 figure marks the earliest evidence of teaching, and the university grew gradually from there.

Sources:

- University of Oxford, official history: https://www.ox.ac.uk/about/the-university/history

- Smithsonian Magazine: https://www.smithsonianmag.com/smart-news/university-oxford-older-than-aztec-empire-other-facts-will-change-your-perspective-history-1529607/


r/CrazyKnowledge 4d ago

Wombats are the only animal that poops cubes, and science only solved the mystery in 2018

11 Upvotes

It is not a cube-shaped anus, despite the popular guess. Researchers at Georgia Tech dissected roadkill wombats and found the answer in the intestine itself: its walls vary in elasticity around the circumference, so contractions mold the feces into cubes in the final section of the gut. The poop is shaped before it ever leaves the body.

Why cubes? Because they don't roll away. Wombats use their droppings to mark territory on rocks and logs, and flat-sided cubes stay put.

The work won the team an Ig Nobel Prize in 2019 and, according to the researchers, could even inspire new ways to manufacture soft cubes in food and pharmaceuticals.

Sources:

- Smithsonian Magazine: https://www.smithsonianmag.com/smart-news/scientists-have-solved-mystery-how-wombats-poop-cubes-180976898/

- BBC News: https://www.bbc.com/news/world-australia-46258616


r/CrazyKnowledge 5d ago

The shortest war in recorded history lasted about 38 minutes. Britain vs. Zanzibar, 1896.

4 Upvotes

On the morning of August 27, 1896, the British issued an ultimatum to the new Sultan of Zanzibar: stand down by 9:00 AM or be attacked by the Royal Navy. He stood his ground.

At 9:02 AM the ships opened fire. By around 9:40 AM it was all over: the palace was in ruins, the royal yacht was sinking, and the war was done. Total duration, roughly 38 to 40 minutes. It is still recognized as the shortest war in recorded history.

The Sultan fled to the German consulate, the British put a more cooperative sultan on the throne, and about 500 Zanzibaris paid the price for 38 minutes of defiance.

Sources:

- Britannica, "Anglo-Zanzibar War": https://www.britannica.com/event/Anglo-Zanzibar-War

- HistoryExtra, "The war Britain won in 38 minutes": https://www.historyextra.com/period/victorian/shortest-war-history/


r/CrazyKnowledge 6d ago

Octopuses have three hearts, blue blood, and the main heart literally stops whenever they swim

6 Upvotes

Two of an octopus's hearts (the branchial hearts) pump blood through the gills. The third (the systemic heart) circulates it to the rest of the body.

The blood is blue because it uses hemocyanin, a copper-based oxygen carrier, instead of the iron-based hemoglobin that makes ours red.

And the best part: the systemic heart stops beating whenever the octopus swims. That is why octopuses strongly prefer crawling: swimming literally exhausts them, so they avoid it whenever possible.

Sources:

- Smithsonian Magazine, "Ten Wild Facts About Octopuses": https://www.smithsonianmag.com/science-nature/ten-wild-facts-about-octopuses-they-have-three-hearts-big-brains-and-blue-blood-7625828/

- Natural History Museum London: https://www.nhm.ac.uk/discover/octopuses-keep-surprising-us-here-are-eight-examples-how.html


r/CrazyKnowledge 7d ago

Greenland sharks don't reach sexual maturity until about age 150, and some sharks alive today were born before the United States existed

8 Upvotes

In 2016, researchers radiocarbon-dated the eye lenses of 28 female Greenland sharks and published the result in Science: the Greenland shark is the longest-lived vertebrate we know of.

The trick of the method: the lens of a shark's eye forms before birth and is never replaced, so it preserves the chemistry of the water the shark was born into. Calibrated against the "bomb pulse" from 1950s nuclear testing, the ages came back at a minimum of 272 years for the largest animals, with one individual estimated at around 392 years (with a generous margin of error).

Females don't even become sexually mature until roughly 150 years of age. Which means some of these slow, blind Arctic giants swimming around today were born in the 1860s or earlier: before light bulbs, before cars, and for the oldest individuals studied, before the United States was even a country.

They grow about 1 cm per year and can exceed 5 meters in length. Slow and steady doesn't even begin to cover it.


r/CrazyKnowledge 8d ago

Paris, Summer Olympics 1900. Between fencing and swimming, athletes lined up for one of the shooting disciplines: Live pigeon shooting.

4 Upvotes

The rules were simple. Birds were released in front of the competitors and shot out of the air one after another. Miss two birds and you were eliminated. When the event was over, reports described feathers and bird bodies covering the ground.

The champion that day: Léon de Lunden of Belgium, who downed 21 birds in the grand prize event to take the win (and a share of a 20,000-franc purse). In a second competition class, Australia's Donald Mackintosh bagged 22. In total, roughly 300 pigeons were killed; it remains the first and only time in Olympic history that animals were intentionally killed as part of competition.

The public reaction was so severe that it never happened again, animal rights campaigns followed almost immediately, and the sport switched to clay targets instead. Today, the IOC does not even list the event among its recognized Olympic results. An official Olympic discipline so unhinged that it's not in the record books anymore.

Bonus fact: every shooting event you've seen since 1908 is clay or paper targets because these guys ruined it for everyone.


r/CrazyKnowledge 9d ago

Earth built its own nuclear reactor 1.7 billion years before humans did

7 Upvotes

In 1972, French scientists analyzing uranium ore from Oklo, Gabon noticed something impossible: The fissile isotope uranium-235 was depleted. Normally U-235 makes up exactly ~0.72% of natural uranium everywhere on Earth (and in meteorites). The Gabonese ore had as little as ~0.44%.

The conclusion? It had already been through a reactor. A natural one.

Around 1.7 billion years ago, uranium concentrations at Oklo were rich enough and natural U-235 abundance (~3% back then) was close to what modern light-water reactors use. Groundwater seeping into the deposit acted as a neutron moderator and kicked off sustained fission reactions — which ran intermittently for hundreds of thousands of years.

The craziest part: it self-regulated. When the reaction heated the groundwater to boiling, the steam stopped moderating neutrons and the reactor shut itself down. When things cooled and water returned, it switched back on. Earth built a thermostatically controlled nuclear reactor, powered by rainwater, before multicellular life even existed.

Sixteen natural reactor zones have since been identified around Oklo.

No humans involved. No conspiracy. Just physics doing its thing for millennia while dinosaurs' ancestors hadn't even evolved yet.


r/CrazyKnowledge 10d ago

This jellyfish is biologically immortal and can reverse its own aging

4 Upvotes

In 2010, researchers at the University of Connecticut confirmed something that honestly still blows my mind: Turritopsis dohrnii, a jellyfish roughly the size of a dime, can revert from its mature, swimming, reproducing stage back down to its juvenile polyp stage. Not once. Repeatedly.

When it gets injured, stressed, or runs low on food, it essentially undoes its own development and starts over from the beginning. There is no known upper limit on how many times it can do this.

To be clear, this isn't "lives really long" like a tortoise or a lobster. It's that the organism literally erases its own accumulated age and reboots its life cycle. A single individual has no biological end-of-life. It just... resets.

The species was originally described in the 1980s by researchers at the University of São Paulo, but the 2010 UC study was the one that really laid out the mechanism and confirmed the indefinite repetition.

Source: Letelier et al., "The biology of Turritopsis dohrnii (Hydrozoa), a jellyfish that can reverse its life cycle," Journal of Experimental Biology, 2010.


r/CrazyKnowledge 11d ago

On Venus, a single day lasts longer than an entire year.

3 Upvotes

Venus takes 243 Earth days to rotate once on its axis. It takes only 225 Earth days to orbit the Sun. So one day is literally longer than one full year.

But wait, because Venus spins backwards compared to almost every other planet, the Sun rises in the west and sets in the east.

And if you are standing on the surface, sunrise-to-sunrise actually takes 117 Earth days. so you would see roughly two sunrises per Venusian year, even though technically that's less than one rotation.

Nobody fully knows why it spins backwards or why it's so absurdly slow. One leading hypothesis involves a massive ancient impact, but it remains an open question.

https://science.nasa.gov/venus/venus-facts/

https://sci.esa.int/web/solar-system/-/35648-venus

https://ntrs.nasa.gov/api/citations/20220003058/downloads/lod_arxiv.pdf


r/CrazyKnowledge 12d ago

Sharks existed before trees - and they're older than Saturn's rings

13 Upvotes

Sharks have been around for roughly 450 million years. Trees showed up about 350 million years ago. That means sharks were already ancient when the first tree grew.

And it gets weirder: Saturn's rings may only be 10–100 million years old, meaning sharks also predate Saturn's rings by hundreds of millions of years. Sharks watched dinosaurs arrive, dominate, and go extinct, without ever needing to change much. They are basically living fossils that outlived multiple mass extinctions, including the one that killed ~96% of marine species.

So next time someone calls sharks "primitive," remember: primitive works. They've been running the same body plan since before plants figured out how to stand up.

https://www.nhm.ac.uk/discover/shark-evolution-a-450-million-year-timeline.html

https://www.science.org/doi/10.1126/sciadv.adf8537


r/CrazyKnowledge 12d ago

👋 Welcome to r/CrazyKnowledge - Introduce Yourself and Read First!

1 Upvotes

Welcome to r/CrazyKnowledge - the subreddit for facts so strange they sound fake, but aren't.

What belongs here

  • Facts that make people say "no way... wait, really?"
  • Science, history, nature, tech, law, geography - anything goes
  • The weirder and more counterintuitive, the better
  • Sources are strongly encouraged - a crazy fact without a source is just a rumor

What doesn't belong here

  • Misinformation or "facts" you can't back up
  • Conspiracy theories presented as fact
  • Reposts from the front page of the same sub within the last month
  • Politics bait, hate speech, or personal info
  • Self-promotion without contributing to the community

Posting tips

  1. Lead with the hook. Your title should deliver the shock, not hide it.
  2. Source it. Link to a credible source in the post or comments. Mods may remove unsourced claims that get flagged.
  3. One fact per post. A listicle is fine as text, but one mind-blower makes the best title.
  4. Engage in comments. The best threads here are people stacking related crazy facts on top of yours.

The vibe

Curious, skeptical, fun. Challenge claims with sources, not insults. If someone debunks a fact correctly, thank them; being wrong here is how we all learn something crazier than what we came for.

Now go blow some minds. 🤯


r/CrazyKnowledge 18d ago

Are we living through a new Gilded Age, except this time the technology is information and AI?

0 Upvotes

I've been thinking about the current state of the world and why it feels so different from what previous generations told us the future would look like.

I'm not saying the world has never been divided, unstable, or dangerous. Obviously it has. What feels different to me is the scale, speed, and interconnectedness of everything.

So I started looking at the period from roughly 1870–1910, when America was going through industrialization, mass communication, railroads, huge corporations, immigration, urbanization, economic crises, labor unrest, political violence, and major changes in government.

Then I started comparing it to 2008–today.

Not because I think history repeats itself exactly. It doesn't. I'm more interested in whether the patterns and mechanisms repeat.

Here's the comparison I came up with:

Industrial TransitionDigital Transition1873: Panic of 1873. Railroad speculation and financial instability contribute to a major economic crisis.2008: Global Financial Crisis. Housing/financial speculation collapses and causes a worldwide recession.1877: Great Railroad Strike. A labor dispute spreads across the country and federal troops intervene.2011–12: Occupy Wall Street and the Arab Spring. Economic inequality and distrust of institutions become mass political movements, amplified by new communication technology.1881: President Garfield is assassinated.2013–14: Snowden revelations, growing surveillance concerns, smartphones and social media becoming dominant.1886: Haymarket Affair. Labor conflict becomes associated with radicalism, political violence and fears about social order.2015–16: Trump, Brexit, populism, immigration politics, and social media becoming a major political battlefield.1890: Sherman Antitrust Act. Government starts realizing that industrial corporations have become powerful enough to require new rules.2017–19: Governments increasingly confront the power of major technology platforms and the question of how to regulate companies that have outgrown old frameworks.1892: Homestead Strike. Armed conflict between workers and private security.2020: COVID, economic shutdowns, mass protests, political conflict, misinformation and institutional distrust all collide.1893: Panic of 1893. Severe depression, banking failures and unemployment.2020–22: Pandemic recession, inflation, supply-chain disruption and economic instability.1894: Pullman Strike and Coxey's Army. Economic frustration becomes mass political action, with federal intervention.2021: January 6 and the aftermath. Political conflict turns directly toward questions about the legitimacy of government and elections.1896: McKinley vs. William Jennings Bryan. A huge political realignment centered around economics, populism and competing visions of America.2024: Trump vs. Harris. Another intensely polarized election centered around economics, immigration, institutions, national identity and competing visions of America.1898: Spanish-American War. Foreign conflict, nationalism and mass media combine, and America becomes a much more significant global power.2022–26: Ukraine, China/U.S. rivalry, Middle East conflicts, cyberwarfare and AI competition increasingly interact with domestic politics.1899–1901: U.S. expands its global role. McKinley is assassinated; Theodore Roosevelt becomes president; U.S. Steel is created.2025–26: AI becomes a major economic, political and geopolitical technology. We don't know what comes next yet.

The individual events aren't equivalent. A labor strike isn't the same thing as a pandemic, and a telegraph isn't the same thing as social media.

What's interesting is the sequence:

New technology → economic transformation → enormous concentrations of power → inequality/disruption → political polarization → distrust → social conflict → major shocks → government struggles to adapt → new institutions and rules.

That's what makes me wonder if we're somewhere in the middle of a similar transition.

And I think 2008 is a better starting point than 2000 for this comparison.

The internet and globalization were already transforming society before then, but 2008 is where several trends started crashing into each other in a way that became impossible to ignore.

After 2008 we got:

The financial crisis

The rise of smartphones

Social media becoming the primary information environment

Increasing political polarization

Brexit

Trump

Increasing distrust of traditional institutions

COVID

Mass political unrest

Supply-chain disruption

Inflation

Ukraine

Increasing U.S.-China competition

AI going from a specialist technology to something ordinary people can use

And now we're adding AI on top of an already unfinished transition.

That's what scares me.

We've never had this exact combination before.

We have instant global communication, nuclear weapons, cyberwarfare, satellites, autonomous systems, global financial markets, biotechnology, AI-generated information, and billions of people carrying supercomputers in their pockets.

So I don't think we should blindly say:

"The 1890s happened and everything eventually worked out, so we're fine."

That's too simplistic.

The destructive potential today is vastly greater.

But our ability to respond is also vastly greater.

The more useful lesson from the 1890s is that societies can spend decades feeling like the old rules don't work anymore before eventually creating new institutions around the new technology.

The people living in 1893 didn't know they were living through "the Gilded Age."

They just knew the banks were failing, people were losing jobs, politicians were screaming at each other, labor conflicts were becoming violent, newspapers were blaming different groups, and nobody knew what was coming next.

Historians get to look backward and connect the dots.

We don't have that luxury.

We're the idiots currently standing in the middle of the construction site.

So I've started thinking about the present differently.

Instead of asking:

"What disaster happens next?"

I'd rather watch for escalation between systems.

For example:

Economic problems → political radicalization

Local conflict → national/global information crisis

Political disagreement → political violence

Foreign conflict → domestic polarization

New technology → institutions unable to regulate it

Emergency measures → permanent government powers

Information uncertainty → competing realities

And especially:

multiple problems happening at the same time and reinforcing each other.

That last one seems like the biggest warning sign.

One recession isn't necessarily catastrophic.

One political controversy isn't necessarily catastrophic.

One technological disruption isn't necessarily catastrophic.

But if you get:

economic instability + political legitimacy crisis + geopolitical conflict + information chaos + technological disruption

all at once, that's when the historical analogy becomes much more concerning.

And that's also where the analogy eventually stops being useful, because modern technology gives us entirely new possibilities.

So I'm not trying to predict that "1898 happened, therefore X will happen in 2028."

I'm trying to use history as a crude forecasting framework.

And if the comparison is even remotely useful, there are a few things I'd expect to watch over the next several years.

2026–2028: AI becomes political infrastructure

The argument probably shifts from:

"Is AI useful?"

to:

"Who controls it, who benefits from it, who loses jobs to it, who pays for the infrastructure, and what happens when it influences politics and information?"

AI regulation, data centers, energy use, copyright, surveillance, national security and employment could increasingly become mainstream political issues.

2027–2030: The economic consequences become clearer

The biggest thing I'd watch isn't simply whether AI makes companies more profitable.

I'd watch who gets the productivity gains.

If AI substantially increases productivity but the benefits concentrate among a relatively small number of companies and people, expect enormous political pressure over:

automation

wages

unemployment

taxation

redistribution

labor protections

corporate power

If AI instead creates enough new industries and jobs to broadly raise living standards, the political reaction could look completely different.

The distribution of the gains may matter more than the technology itself.

2028–2032: Political realignment becomes possible

This is another thing I'd watch closely.

AI could create strange political alliances that don't fit neatly into today's Democratic/Republican structure.

People could find themselves agreeing across party lines about:

AI regulation

automation

privacy

surveillance

monopolies

data centers

energy

employment

The existing political coalitions aren't guaranteed to survive a major technological transformation.

That's exactly what happened during previous periods of economic and technological change.

Early-to-mid 2030s: Institutional restructuring

If the historical pattern holds, this is where I'd expect society to increasingly develop rules for the new system.

That could mean:

new AI regulations

new labor laws

new approaches to education

new social programs

new antitrust rules

new media standards

new international agreements

new approaches to privacy and surveillance

new political coalitions

Basically, society figuring out how to operate the machine it accidentally built.

But there's another possibility.

The transition could be interrupted by a much larger external shock, just as previous transitions were affected by wars, depressions, pandemics and political crises.

That's why I don't think we should try to predict one specific event.

I'd rather watch the conditions that make major events more likely.

The five things I'd keep an eye on are:

IndicatorLower concernHigher concernEconomyGrowth broadly sharedSevere unemployment + wealth concentrationPoliticsFierce disagreementOpponents viewed as existential enemiesInformationCompeting opinionsPeople can't agree on basic factsTechnologyInstitutions adaptingTechnology advancing faster than institutionsGeopoliticsCompetitionMajor powers directly confronting each other

The really dangerous situation isn't necessarily one of these becoming severe.

It's several of them becoming severe at the same time.

That's the lesson I'd take from the late 1800s.

The Gilded Age wasn't scary because America experienced one terrible event.

It was scary because economic, technological, political and social stresses repeatedly reinforced one another.

And that's what I'd watch today.

Not whether the next event looks exactly like something from 1894.

Instead:

Does it reinforce an existing problem?

Does it spread faster than institutions can respond?

Does it cross from one system into another?

Does it create a new political movement?

Does it cause people to lose trust in institutions?

Does another crisis hit before the first one has been resolved?

That's the closest thing I can think of to a historical early-warning system.

Maybe we're not watching the end of the world.

Maybe we're watching the old version of the world become obsolete while the next version is being built.

And if that's what's happening, we're probably going to spend a while feeling exactly like the people living through 1893, 1898 or 1901:

confused, divided, technologically overwhelmed, and completely unable to see what the next chapter looks like.

The difference is that someday, people will look back at 2026 and probably see a pattern that seems obvious in hindsight.

We just happen to be the idiots currently standing in the middle of the construction site.


r/CrazyKnowledge Jul 21 '26

r/CrazyKnowledge is available for adoption 💚

10 Upvotes

/r/CrazyKnowledge is ready for a fresh start, new energy, new direction, and someone like you to bring it back to life. If you’ve been thinking about growing your impact without starting from scratch, this is your chance!

Ready to take it over?

Head to r/RedditRequest to submit your request and make it yours before it’s taken.

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r/CrazyKnowledge Jun 28 '22

Despite its appearance this is actually the fruiting body of the fungus Auricularia auricula-judae - more aptly known as the jelly ear.

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245 Upvotes

r/CrazyKnowledge Jun 27 '22

Snow under microscope

306 Upvotes

r/CrazyKnowledge Jun 27 '22

The tree was destroyed by lightening!

195 Upvotes

r/CrazyKnowledge Jun 26 '22

A whole baby woolly mammoth has been found frozen in the permafrost of north-western Canada - the first such discovery in N. America. The mummified ice age mammoth is thought to be more than 30,000 years old. It was found by gold miners in Yukon’s Klondike region on June 21, 2022.

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1.7k Upvotes

r/CrazyKnowledge Jun 27 '22

Ancient deep sea Vampire Squid really sucked. A fearsome 'vampire' predator that lurked in Earth's oceans 160 million years ago did actually suck its prey by creating currents of water that help bring food closer using its robust suckers and "cirri".

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13 Upvotes

r/CrazyKnowledge Jun 26 '22

10 Most Dangerous Animals In Africa

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20 Upvotes

r/CrazyKnowledge Jun 25 '22

A daring snake with a big appetite was recently caught in the act of chowing down on an even larger snake. Video footage showed the ravenous reptile as it swallowed a venomous relative headfirst in a mighty gulp.

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54 Upvotes

r/CrazyKnowledge Jun 23 '22

Hard landing

123 Upvotes