True Facts: Snake and Lizard Tongues
Dr. Kurt Schwenk
It was a pretty incredible gift to be able to work with Kurt on this episode. His work spans decades and it took multiple tries to understand it in a way that could be put together in a narrative. I am very grateful for all of his time, warmth and generosity. I had to leave many, many wonderful pieces of research and factoids out due to time constraints but I would urge any of you that are interested to dive deeper into his work.
His colleagues Dr. William G. Ryerson, Ms. Amanda E. Hewes and
Ms. Sara Horwitz contributed a great deal to some of the research that I mentioned.
Dr. Margaret Rubega ( deserves thanks for introducing me to Kurt in the first place.

Additional footage licensed from:
Envato Elements

  • Chris L.
    Chris L.

    "This tongue will blow your mind." That's what she said.

  • Crystal Thueringer
    Crystal Thueringer

    My favorite commentary so far!!!

  • EfahTheEmo

    ZeFrank taught me more than any biology teacher ever could, whilst being 1000× more funny than any teacher period

  • SickMade Macie 801
    SickMade Macie 801

    When humans do this it's called an HR violation lol

  • Joy

    3:27 'One of those ink blots that the brain witches make you look at' ... 😆

  • Real Nito
    Real Nito

    Dr. Schwenk needs some more appreciation

  • Karnaras Anargyros
    Karnaras Anargyros

    Late at night , when I can't sleep , I come to this corner of youtube to make myself numb

  • Sadenna Swafford
    Sadenna Swafford

    Q: would you consider doing one on the Watusi Bulls? I am sure you would love to research the facts on them!

  • Texas Red
    Texas Red

    "are the new viewers gone yet?" No its so funneh

  • Elroy da shogun
    Elroy da shogun

    Me:Isnt a worm lizard a snake The scienctist:imma slap the shit outta yah

  • Autumn Mentink
    Autumn Mentink

    "Are any viewers gone yet?" I'll admit I was eating breakfast and very nearly was.

  • aristideau

    the double entendre 'dad jokes' are really ugh

  • Jar Ray
    Jar Ray

    u know, when i first heared of the guy Jerry i thought he was me as my name was also Jerry

  • PuPOp Pankek
    PuPOp Pankek

    Do more videos about oppih

  • tigress63

    There should be a video on the fig wasp

  • stu booth
    stu booth

    Today's drinking game. Scroll through the comments, take a swig every time you see a direct quote from the vid. Good luck.

  • michel perreault
    michel perreault

    Thank you so much for putting a smile on my face. Very funny to watch.

  • Sack fu
    Sack fu

    So reptiles use their demon tongues to lick the ground, then snort up whatever they find through their mouth nostrils. Because snakes apparently have nostrils on the roof of their mouths.

  • Basil Southey
    Basil Southey

    This is literally the best example of science communication I have EVER seen. Going to show this to classes I teach.

  • Anne Bruecks
    Anne Bruecks

    I have now learned more interesting and in detail info than I did in 12 years of public education.

  • Krysta Monique
    Krysta Monique

    😹😹😹😭 “Brain witch”

  • Nate Gawlik
    Nate Gawlik

    Have you ever done a video on flatworms? I’m sure this would be entertaining

  • Laure_lei

    Freaking hilarious, and what a champ the Doc is. Thank you for all the work that goes into these!!!!!

  • Ano N. Ymous
    Ano N. Ymous

    1:42 cute hognose

  • glfmn

    TRUE FACTS ABOUT ORCHIDS A lot of orchids use sexual deception to get pollinated, and all kinds of other crazy strategies that often involve being mean to insects.


    “When humans do it it’s called an HR violation” ahhh I love this channel lmao

  • Benedict Zafra
    Benedict Zafra

    How Is Teddy?

  • 2balive1

    Hey Frank. As one genius to another, I propose a market that will over double your cash market. I have always loved your humor and attention to detail. I know that this is only a love of leisure that you don't really need. Thank you for keeping on. You have the capacity to educate young minds with your great humor! If you are willing to make videos for children , you have the chance to grow greater than Bill Ney the "science guy". I would love to see you share your knowledge and humor with my son. He's 10. Please create this page. You might even get picked up by PBS if you do it right

  • john kleinsmit
    john kleinsmit

    zefrank. you need to teach public speaking at a local school

  • R S
    R S

    I'm just bummed out that he didn't pronounce "tongue" as "tongewwwwwrr". Otherwise it was brilliant.

  • craxy d
    craxy d

    no matter how bad i feel, you make me laugh,love your vids. they keep me same in the insane world of 2020

  • Jaylilah

    Pure, frikken brilliance! One of your best Zefrank!

  • cyberhawk80

    when humans do it , it's called an HR violation.. thanks for the laugh in these dark times..

  • The Latvian Corsair
    The Latvian Corsair

    0:40 Somebody's gonna get pregnant.

  • Dustin Ontaiyabbi
    Dustin Ontaiyabbi

    We need to enjoy Zefrank while he is here. He's 48 years old.

  • Garret Key
    Garret Key

    A few ideas. Platypus, otter, komodo dragon, spitting spider, moose, skunk, casowary bird.

  • Ladyhawk's Lair
    Ladyhawk's Lair

    This was very informative. Seriously. I'm gonna need to watch this video again...and then get super slow-mo footage of my hognose snake's tongue. That perv, Dr. Schwenk, might pay me for it. J/K ;) I'm super impressed he figured out all this stuff.

  • A Mark
    A Mark

    I love you so much so I just would like to take a moment and type out the appreciation. I appreciate this so much because this is a lot of time and effort and I'm learning So thank you lol

  • Ladyhawk's Lair
    Ladyhawk's Lair

    6:21 "Are the new viewers gone yet?" XD I've loved _True Facts_ for years, but a friend of mine can't get past the Morgan Freeman voice. I'm tempted to tell him: "Morgan Freeman, Morgan Freeman, Morgan Freeman, Morgan Freeman...Morgan Freeman. Morgan. Freeman."

  • A Mark
    A Mark

    Omg you know what I just thought of ..... this😑this😑this is like The Adult Swim of Animal Planet 🤫🤣

  • David Weiller
    David Weiller

    Wow, fascinating video! Here is my take of an 🐍 Eyelash viper flicking its forked tongue:

  • Katherine White
    Katherine White

    I finally lost it at "snowman's baby maker"

  • snikrepak

    Hr violation!!!!! Hahahahahaa

  • gottabesandi

    Thanks. Now I can never unsee a slow motion mouth blowing a raspberry. 👁👅👁

  • Edward Tiangco
    Edward Tiangco

    I guess I'm a perv as well. 😅

  • life time
    life time

    Dear Ze frank We mostly want true facts about a human. Please because thats how we do Sincerely -Life_Time0s

  • Doofus_ow

    At 6:49... Holy shit that had to b one of the best

  • краб

    Why is your voice so soothing?

  • Sung Ji
    Sung Ji

    You're back!

  • Chandra Satrio
    Chandra Satrio

    I swear to God, ZeFrank's work is just getting better and better but I couldn't tell which video that started it all. He seems just to start from 100 and just keep going forward.

  • PreBound

    Man, the laughs just don't stop when watching this. Comedic gold.

  • Kaido Vesternin
    Kaido Vesternin

    oh my god the lizard with its leg-parts in the air, I could almost hear it go "weeee, look mom, no hands!"

  • Felix

    That timeline of all the funny moments he made had me dying! He seems like a great guy!

  • Chaotic Good
    Chaotic Good

    This is how everyone should should learn about animals

  • Jürgen Kun
    Jürgen Kun

    what that tongue do 😏

  • DB


  • savana muddypaws
    savana muddypaws

    Looks like Trump's tongue. #Stopthestupid Trump!

  • bassmith448 bassist
    bassmith448 bassist

    Love the boobie music at the end too. Funky grooves in da house!!!!!!!

  • Jessie Jubilee
    Jessie Jubilee

    “Can’t fool me brain witch.” 🤣

  • bassmith448 bassist
    bassmith448 bassist

    I died when you said sinus infection!!!!

  • Leah C
    Leah C

    4:25 made me die

  • LegendPhantom

    Looks like not only gonna blow my mind*

  • Kokichi's_Expired_Panta

    POV: You're here from teddy has an operation

  • Hallebumba

    i want: Costasiella kuroshimae

  • Proudly Brown
    Proudly Brown

    "you try this. Try flicking your tongue up and down very quickly. When humans do this its called HR violation". One of the many jules.

  • Simond Frost
    Simond Frost

    Bro, I died when he said HR violation. Your a genius!

  • ChogMils

    uhh how about true fact about zefrank1

  • LionGaming

    i love this Chanel

  • Korok Seed
    Korok Seed

    I’m not gonna lie, this was actually super interesting

  • Torti Tongue
    Torti Tongue

    I recognize your voice from dear kitten! Or you may not be the person who voiced/narrated in it... sorry if you weren’t, you got a very nice voice and some very funny content here though friend XD

  • Fluffy waffles fw.
    Fluffy waffles fw.

    The end card terrifies me

  • pluspiping

    Is this the kind of page where I can say "I'm always a slut for fluid dynamics" and people will, like, Get It? Love the in-depth sciencey ness of this video, it's a real treat, and thank you Dr. Schwenk!

  • Martin Friman
    Martin Friman

    Shit, this was seriosly educational 😅

  • FedBiker

    The sound at 8:31got stuck halfway between my hippocampus and neo-cortex and is now on infinite loop.

  • R3DLiFE

    lmfao !!!! factfull and funny !

  • Greer McNally
    Greer McNally

    'I'll give an arm and a leg to be the best at it' is now what I'm going to refer to whenever I talk about snakes.

  • DeathLotus

    "When humans do this it's called an HR violation"🤣

  • charizard4321

    Next time I see a snake I'm going to ask it what that tongue do😂😂

  • Muneerah Adams
    Muneerah Adams


  • Kevin Parks
    Kevin Parks

    Please do a video on the small and well named bird called a bushtit...

  • rc casano
    rc casano

    “When humans do this, it’s called HR Violation” The ending: 10:18

  • Rafael Pasito
    Rafael Pasito

    When human do its called HR [human rights] violations! Hahahaha LoL

  • Twisty99

    Where is teddy now?

  • MsSaraKirkpatrick


  • MsSaraKirkpatrick

    Dammit, Jerry! Get it right! One minute in, and we're already yelling at you MULTIPLE TIMES!


    Teddy is still alive?

    • Twisty99

      Probably not

  • Stormy Davis
    Stormy Davis

    God I want to go to therapy so I can call the therapist a brain witch despite their repeated insistence I stop.

  • Muglorgrimlockable

    8:30 I rewound and even slowed it down me and the misses are dying and also copying it all day going randomly.....BLBMBMBLL

  • Christian Terry
    Christian Terry

    This tongue will blow your mind. That’s what she said

  • codeman7055

    You should make videos for whales and sharks

  • S CO PO
    S CO PO

    All these lizards give me Schwenks

  • Jesus jiu-jitsu
    Jesus jiu-jitsu

    Use this as a "I was today years old when I found out worm lizards were a thing" button.

  • Asani Williams
    Asani Williams

    That mouth at the end was traumatizing

  • Peter Meuller
    Peter Meuller

    “When humans do this it’s called an HR violation” 😂😂😂😂😂😂

  • Hunter Clwminsom
    Hunter Clwminsom


  • Anna Mishonova
    Anna Mishonova

    I self-identify as a smarty nipple

  • Pumkinn

    wheres mr teddy

  • Jose Arellano
    Jose Arellano

    HR violation 🤣🤣💀💀

  • TheOnlyRealTapir

    HR violation :DDDD

  • Samuel Varga
    Samuel Varga