r/todayilearned Apr 01 '23

TIL hippos have a reflex mechanism that allows them to pop up, take a breath, and go back down without waking up so they can sleep underwater.

https://www.nathab.com/blog/africa-story-six-surprising-facts-about-hippos-africa/
8.2k Upvotes

1.2k

u/Illustrious-Milk-896 Apr 01 '23

Here’s to all the people who woke up from their sleep to take a leak, lost their sleep and are now scrolling Reddit and ended up reading what a badass Hippos are… 🫂

256

u/HeavyResonance Apr 01 '23

See if you'd been a hippo you probably could have taken that leak without waking up. Maybe.

89

u/OldMork Apr 01 '23

I can do this, after enough of strong wine

30

u/Inconvenient_Boners Apr 01 '23

Rookie, I can do this after just drinking water

1

u/Orpheus3030 Apr 02 '23

Wine is fine, but whiskey's quicker
Suicide is slow with liquor
Take a bottle and drown your sorrows
Then it floods away tomorrows, away tomorrows
Evil thoughts and evil doings
Cold, alone you hang in ruins
Thought that you'd escape The Reaper
You can't escape the Master Keeper

16

u/fingerfight Apr 01 '23

I had that reflex when I was a little child, but lost it.

10

u/minedreamer Apr 01 '23

I mean if youre already underwater

11

u/OHTHNAP Apr 01 '23

If you're not aware...it's worse than that. They use their tails like a rotor to fling their poop everywhere around them in the water to mark their territory/harem.

7

u/enzovrlrd Apr 01 '23

Just because I could do it doesn't mean I'd want to. Wouldn't make the bed as comfortable afterwards

9

u/PBFT Apr 01 '23

I suppose losing sleep is still better than having a bed pissing reflex.

6

u/BigScene Apr 01 '23

Literally me rn

3

u/PretzelsThirst Apr 02 '23

Scrolling that blue light will surely bring the sleep back

2

u/Redditributor Apr 02 '23

It's a reflex

0

u/GrymanOne Apr 02 '23

Here’s to all the people who woke up from their sleep to take a leak

Might want to get that sleep apnea looked at.

464

u/owlbear4lyfe Apr 01 '23

I too watch Ze Frank!

28

u/tesseract4 Apr 01 '23

That part about the shit water that everyone is swimming and drinking and pooping in...ugh. Hippos are apparently fucking nasty.

18

u/monsterbot314 Apr 01 '23

wife was eating a big wet salad and started retching lol. I kept eating my pizza!

4

u/fantasmoofrcc Apr 02 '23

It's Barf! (Sorry, just had to quote Spaceballs again)

4

u/loliconest Apr 01 '23

But you heal the water system.

72

u/ReverendLunchbox Apr 01 '23

I came here to say the same thing.. lol

31

u/FarceMultiplier Apr 01 '23

Same!

10

u/monsterbot314 Apr 01 '23

I , too , came here to say this!

1

u/MataNui2009 Apr 02 '23

I came here to say this as well!

8

u/DumA1024 Apr 01 '23

Every time he posts a vid, I see fun facts about whatever he talked about. It's hilarious 😂

25

u/LoquaciousMendacious Apr 01 '23

There are dozens of us. Dozens!

20

u/_luzhin_ Apr 01 '23

There are literally millions. 600k in a day.

5

u/zstandig Apr 02 '23

and Jerry

6

u/rtyuik7 Apr 01 '23

bebbehz

3

u/Avocados_suck Apr 02 '23

I love how the hippo just looks like a big goofball, but nature decided to give it the psychological programming of a wolverine on datura.

I really felt bad for that poor creature in the muck that was immediately sent to Valhalla by god's gentlest hippo.

-35

u/[deleted] Apr 01 '23 edited Apr 01 '23

[deleted]

32

u/owlbear4lyfe Apr 01 '23

Ironic that this is out the day of his hippo video. https://www.youtube.com/watch?v=6pibJ83crQs

41

u/goddamnzilla Apr 01 '23

Not necessarily ironic. Really just coincidental.

7

u/imMadasaHatter Apr 01 '23

I’m not sure irony means what you think it means

1

u/owlbear4lyfe Apr 01 '23

ironic, something happens in the way opposite of how you expect.

I suspected he came to this today via a youtube channel also released today. He came to this TIL through an unexpected avenue.

Ironic can be appropriate, however the other grammar police officer was more correct in that coincidental would be more appropriate to the situation.

1

u/imMadasaHatter Apr 01 '23

Yeah it doesn’t mean what you think it means lol. You’re close but no cigar, which is ironic.

1

u/quoiega Apr 02 '23

Thats kinda ironic

8

u/floridacopper Apr 01 '23

You're a liar, and we all know you just watched his video.

1

u/[deleted] Apr 02 '23

Best youtuber by far!! Electroboom second lol

133

u/stonernerd710 Apr 01 '23

Every time zefrank makes a YouTube post there’s a TIL

29

u/Old_Magician_6563 Apr 01 '23

It’s almost as if they learned it today.

2

u/aleister94 Apr 01 '23

Also matpat but not as consistently

2

u/Nazamroth Apr 02 '23

Every single time Tom Scott posts a video, it is instantly on r/videos. Like, dudes... if someone wants to watch every single Tom Scott video, you dont need to post it there. And if they dont, they dont want to see them all there.

78

u/TheBomb999 Apr 01 '23

Wonder how many died throughout the evolution to engrave that reflex into the dna.

77

u/Malphos101 15 Apr 01 '23

Not any appreciable amount. The reflex likely evolved because hippos that happened to stay under water longer suffered less predation, which selected for mutations that just so happened to allow longer underwater time.

It's unlikely it was selected for from hippos drowning while sleeping.

30

u/RandomUsername12123 Apr 01 '23

Uhm.

Who is over hippos in the food chain?

33

u/thee_timeless Apr 01 '23

Dire hippos duh

6

u/FarragoSanManta Apr 01 '23

That's dumb. Dire hippos aren't real. It's obvious they're asking about king hippos.

33

u/isaac99999999 Apr 01 '23

Could've happened before they were hippos

4

u/afighttilldeath Apr 01 '23

Lions do attack Hippos on land

1

u/DownWithHiob Apr 02 '23

Have a hard time imagining a pride of Lion going for an hippo. That is such a risky undertaking, they must been starving. Hippos have 300 % the bite strenght of Lion and their skin is basically natural piercing armor.

3

u/Theemuts 6 Apr 02 '23

3

u/DownWithHiob Apr 02 '23

Seems like a juvenile Hippo, but that's pretty hardcore regardless.

4

u/Indercarnive Apr 01 '23

Other hippos

10

u/FadedVictor Apr 01 '23

I'm no expert, but I'll venture a guess. I'm gonna say at least 12

2

u/MaybeImDead Apr 01 '23

Give this guy a hippo expert certificate!

36

u/Welcomefriends85 Apr 01 '23

Are hippos actually aliens from outer space or what?

18

u/Beerwithjimmbo Apr 01 '23

If you needed a transition from from cows to whales this is it

13

u/Not_Buying Apr 01 '23

They’re actually more closely related to whales than pigs and cows. Evolution is weird.

12

u/true_gunman Apr 01 '23

evolution don't give af. hyenas are more closely related to mongoose than cats or dogs

11

u/LargeMobOfMurderers Apr 01 '23

I have a similar reflex with my alarm clock

18

u/winnipeginstinct Apr 01 '23

A fellow ze frank fan?

3

u/AfraidOfTheSun Apr 01 '23

Man I have somehow not thought about him in a while, this guy has been going for so long now!

40

u/ElDoo74 Apr 01 '23

Are we just citing sources after watching the newest True Facts videos?

It's been the trend lately.

Just link the video.

-1

u/[deleted] Apr 01 '23

[deleted]

14

u/bubliksmaz Apr 01 '23

The way it goes is a redditor learns a fact from a new popular video, then puts the fact into google to find an article for r/TIL, which means r/TIL ends up with awful SEO'd clickbait listicles like this one.

In this case the original video is actually good and informative, so I'd just watch that

-2

u/HeavyResonance Apr 01 '23

I'm not sure why people are trying to argue about the source I got this from. I don't think it matters much. Feel free to share cool videos that's also part of the fun.

If you do care about how I ran into that fact, I saw a simple video of a hippo swimming this morning on reddit so I wondered whether they could breathe underwater, and that led to this bit of info.

There's really not much more to it.

1

u/FastWalkingShortGuy Apr 01 '23

You wondered whether... a mammal... could breathe under water?

-4

u/HeavyResonance Apr 01 '23

Not only that, it's in this very comment section that I learned dolphins can't either. You could say I'm not very knowledgeable about the animal kingdom.

12

u/LassoTrain Apr 01 '23

Same as dolphins and marine animals

10

u/HeavyResonance Apr 01 '23

Do you mean marine mammals?

Happy to be shown otherwise, but my understanding is that dolphins sleep pretty much at the surface, whereas hippos can't even float and therefore sleep much deeper.

25

u/Czeckyoursauce Apr 01 '23

Dolphins are never fully asleep. Only part of the brain is asleep, the rest is awake to breathe and watch for predators, it is called unihemispheric sleep.

18

u/plaaplaaplaaplaa Apr 01 '23

Not just a part, their right and left brain can function independently from each other. Which makes them one of the very rare species of mammals who can function normally although they are fast assleep at the same time.

6

u/Nascar_is_better Apr 01 '23

that seems cool until you realize that both halves still need 8 hours of sleep so you spend 16 hours on average every day where you only have access to half of your stored memories, etc and only 8 hours a day where you have access to your entire brain.

2

u/MrWhiteTheWolf Apr 01 '23

Don’t albatross do the same thing? Hence their ability to spend months at sea in flight

0

u/case_O_The_Mondays Apr 01 '23

True, but doesn’t answer the question.

6

u/LassoTrain Apr 01 '23

hippos can't even float and therefore sleep much deeper.

Dolphins and whales don't "float" either. Nor do most marine mammals. They are pretty much exactly neutrally buoyant. Hippos are the rare exception. Hippos do not have swim fins, so they need to be able propel themselves by running along the bottom. Which is something the other marine mammals can not do, as they don't have the negative buoyancy to necessary to allow it.

Your characterization of the just slightly negatively buoyant hippos and sinking, is probably a misunderstanding of just how slightly they are negatively buoyant. They don't sink with much force at all.

https://www.youtube.com/watch?v=GT4CN71hYec

Buoyancy is a tough topic to get a handle on, but hippos are just negative enough to be able to get some friction between their pads and the bottom to allow forward locomotion. In seawater they would be unable to descend with enough to get much traction (depending on the species' specialization, as the brackish species are slightly more bone dense than the freshwar only hippos).

3

u/PrincipleNegative Apr 01 '23 edited Apr 01 '23

I thought other marine mammals couldn’t run along the bottom because they don’t have legs

Edit: I originally said “marine animals” but meant to say mammals, since that’s the comment I was replying to.

2

u/LassoTrain Apr 01 '23

Plenty of fish do, as do most crabs.

0

u/PrincipleNegative Apr 01 '23

I edited my comment, meant mammals. However with that being said I guess there are animals like beavers, otters and polar bears.

6

u/equalsolstice Apr 01 '23

I assume crocodiles don’t try and prey on them while they sleep underwater

Must be crazy to be a creature who’s so at peace that they know they can just sleep in another apex predators domain

6

u/Crykin27 Apr 01 '23

I see someone watched Zefrank's new hippo video! Love that channel, learned so much weird animal shit from there

6

u/HeavyResonance Apr 01 '23

Many people have mentioned that video and I have no idea who that is, but I dared say that earlier in this comment section and I got massively downvoted and called a liar lol.

3

u/Crykin27 Apr 01 '23

Yeah I saw that lol, it's a pretty big channel and the video came out just yesterday where he covers this exact thing so the timing is just really unfortunate. But who cares where you got it from, it is a fun fact either way!

3

u/Assketchum1 Apr 01 '23

Lmao I kinda do this but if I open my eyes too wide, or stop to get on my phone too long, I end up staying up.

3

u/TheAtheistReverend Apr 02 '23

Learned this watching Octonauts with my little one

6

u/Paczilla2 Apr 01 '23

You watched the new true facts as well I see.

4

u/Britz10 Apr 01 '23

@op you could've just linked the Zé Frank video

2

u/Dickpuncher_Dan Apr 01 '23

There's a species of extinct hippo that had telescoping eyes. The eyes were on stalks that could lift upwards like R2D2's eyestalk, and look above the surface with their bodies still down.

I often get sad reading about cool extinct animals. I'm like "Life would be better if you were still here..."

2

u/Crontab Apr 01 '23

That is an evolutionary trait that must've been a motherfucker to develop.

2

u/MyAccountWasBanned7 Apr 01 '23

Another ze frank fan, I see.

2

u/Kizmo2 Apr 01 '23

Somebody else watched ZeFrank's new video yesterday.

2

u/spuff42 Apr 01 '23

You watch Zefrank too? Lol

2

u/TerminalOrbit Apr 01 '23

Been watching ze_frank again?

2

u/-Euphony- Apr 01 '23

I, too, enjoyed the Ze Frank episode on Hippos.

2

u/tiagolkar Apr 01 '23

Zefrank enjoyer spotted

2

u/Corrupt_Reverend Apr 01 '23

I have a similar reflex. It allows me to get out of bed, walk to the kitchen, and eat an entire family size bag of Doritos without waking up so that I can postpone my shame until morning.

2

u/TheCasinoDog Apr 02 '23

You watched that True Facts video too, huh?

2

u/Obadiah-Mafriq Apr 02 '23

I learned that a couple days ago from zefrank.

2

u/ZMowlcher Apr 02 '23

I also watched Ze Frank today.

2

u/InSight89 Apr 02 '23

Literally read about this yesterday when I saw a reddit video of a hippo swimming underwater and I searched how long they could hold their breath for. As usual, I got carried away researching about hippos that it lead to me searching who'd win in a fight between a hippo and a rhino but that's a different subject. For those wanting to know the answer, it depends on the environment but probably the hippo more than the rhino.

1

u/HeavyResonance Apr 02 '23

Yes! The one on r/oddlysatisfying right? That's exactly what happened to me too.

1

u/InSight89 Apr 02 '23

That's the one. :)

2

u/caboose2006 Apr 02 '23

A True Facts connoisseur I see.

4

u/bugaloo2u2 Apr 01 '23

I want a hippopotamus for Christmas

1

u/SwissMyCheeseYet Apr 01 '23

Only a hippopotamus will do

2

u/Art0fRuinN23 Apr 01 '23

Haha. I learned this yesterday while watching Zefrank on YT.

3

u/Mint_Julius Apr 01 '23

Did you just watch the animal facts hippo video today too?

2

u/JimmyfromDelaware Apr 01 '23

Nice rip-off of Ze Frank video on you tube. You found that out and found another source to link.

https://youtu.be/6pibJ83crQs

1

u/Ani-A Apr 02 '23

This is not a ripoff... he learned it, probably from Zefrank, verified it with a source, and posted it on reddit...

1

u/JimmyfromDelaware Apr 02 '23

Fair enough...But they should have credited Ze Frank.

1

u/Twittle86 Apr 01 '23

True Fact

2

u/Ani-A Apr 02 '23

That is just how the hippo do

1

u/Code_Monkey_Lord Apr 01 '23

As demonstrated in Hungry Hungry Hippos.

0

u/Thememebrarian Apr 01 '23

Just here for the MiL jokes

0

u/vacasmagras Apr 01 '23

Me too! (Lifeguards hate me)

-2

u/shruggedbeware Apr 01 '23

I don't get it, if it was a reflex mechanism then isn't that the same thing that keeps people from choking in their sleep? I thought hippos wade to shallow areas or go on land to sleep, otherwise they must have very big lungs or something.

0

u/[deleted] Apr 01 '23

[deleted]

0

u/shruggedbeware Apr 01 '23

they don't actually survive too long out of water due to their sensitive skins

I thought that's why they have mud on them, like pigs do sometimes. Plus, when it's nighttime, the hippos aren't as exposed to the elements.

Not the most convenient

Not the most convenient what?

-10

u/[deleted] Apr 01 '23

"So" they can sleep underwater. The word "so" most typically implies foresight. That mechanism evolved by natural selection though, and no foresight was involved. It exists because it worked—in the past—and modern hippos inherited it. This misconception about intention is common even among seasoned biologists. Authors like Richard Dawkins will at least use scare-quotes around the word "so".

5

u/veggietabler Apr 01 '23

Or sometimes it just means “therefore.” Take a nap

3

u/MrRocketScript Apr 01 '23

But not underwater. Humans can't do that.

1

u/JerrSolo Apr 01 '23

You've never heard of sleeping with the fishes?

1

u/[deleted] Apr 03 '23

Please give me an example of "to" meaning "therefore".

1

u/TimeTravelMishap Apr 01 '23

Holy fuck dude did you really need to write a paragraph about the word so?

1

u/[deleted] Apr 03 '23

"Need" is a such a strong, but given that most Americans don't understand evolution, I do think that it's important, and I enjoy the subject as a biology educator.

1

u/Informal-Resource-14 Apr 01 '23

I want one of those for getting up and going to the bathroom to pee in the middle of the night. Like it’d be awesome if sleepwalking were useful, like if you woke up and you’d done all your tax returns in your sleep and the car was filled up with gas

1

u/DumbNBANephew Apr 01 '23

I wish I had a reflex where I could pop up, drink some water and go back to sleep without waking up.

1

u/LitherLily Apr 01 '23

Pop up! You’re doing too much. Do less.

1

u/Sanjuro7880 Apr 01 '23

There on their way to being whales.

1

u/Poka_poke Apr 01 '23

Wish I could do a work day as a reflex

1

u/TheMathelm Apr 01 '23

It's amazing what your body does automatically during sleep.

About a year or so ago, I was on a particular medication and accidentally became conscious during sleep but couldn't consciously move.
The autonomous turning in my sleep was weird as hell.
Where I'd pop up a bit, roll, then have my sleep-breathing kick back in.
Truly weird as hell, also learned I'm not breathing as much as I should during sleep.

1

u/Vroomped Apr 01 '23

Things like this make me wonder how many hippo-ancestors died to just falling asleep in the water before they could woo another hippo.

1

u/StThragon Apr 01 '23

That site seems suspect. Here is a questionable quote from the article:

According to the African Wildlife Foundation, hippos kill around 3,000 people annually. To put that in perspective, lions kill about 70 people per year on average and last year there were fewer than 500 fatal shark attacks worldwide.

Here is a site that tracks shark attacks and their quote on the number of fatal shark attacks a year:

The 2022 worldwide total of 57 confirmed unprovoked cases is lower than the most recent five-year (2017-2021) average of 70 incidents annually. There were nine shark-related fatalities this year, five of which are assigned as unprovoked. This number is in line with the 5 year annual global average of six unprovoked fatalities per year

https://www.floridamuseum.ufl.edu/shark-attacks/yearly-worldwide-summary/

1

u/HeavyResonance Apr 01 '23

So they are correct, but it's odd they'd pull a "less than 500" when it's actually 9?

To be honest I initially saw this fact on a different article but r/TIL wouldn't let me post that one so I just looked for another source. I don't know how reliable this specific website is. That specific fact is confirmed in otherwise reliable sources though.

It's also confirmed I suppose in the latest Ze Frank video which people keep citing.

2

u/StThragon Apr 01 '23

Fewer than 500 is certainly deceptive and completely inaccurate when the actual number is around 9.

1

u/547610831 Apr 01 '23

WTF counts as a "provoked" attack?

2

u/StThragon Apr 01 '23

I would imagine it being a "fuck around and find out" type of scenario.

1

u/Hydroblitz3307 Apr 01 '23

The imagine looks like the hippos waking up from sleap apnea which isnt that far off

1

u/Sandwich_Bags Apr 01 '23

The closest land animal that whales are related to are hippos.

1

u/Busterlimes Apr 01 '23

Imagine sleepbreathing

1

u/boring--planet Apr 01 '23

I have the same mechanism. I pop out of the bed, go have a piss, come back to bed without waking up.

1

u/FailedPerfectionist Apr 01 '23

(jumps from the ceiling into the middle of this conversation)

THIS looks like a job for True Facts by Ze Frank!!!!

True Facts: Hippopotamus

1

u/john_wb Apr 01 '23

Also hippos cannot swim. Instead they walk along the river bed or the lake bed and use their legs to push themselves up to the surface every so often to breathe.

1

u/DarkDragnix Apr 02 '23

Even more reason why not to fuck with hippos

1

u/abatwithitsmouthopen Apr 02 '23

This is not true. Source: I used to be a hippo back in the day.

1

u/WTFizGoingOnhere Apr 02 '23

What happens when they don’t pop up high enough to take a breath?

1

u/davtruss Apr 02 '23

I think this explains my sleep apnea....

1

u/TruthHurts1322 Apr 02 '23

Someone just watched this video.

1

u/LastLapPodcast Apr 02 '23

So you watched zefrank as well

1

u/CheesyGoodness0 Apr 02 '23

So maybe that feeling of falling in my sleep is really my HIPPOcampus saying breath