Why Some Parasites Are Actually GOOD (And Which Can Kill You)

1,116,735
0
Published 2021-09-19
When we think parasites, we often think of illness, disease, and discomfort. But did you know some of them can actually be helpful? Join Stefan Chin and learn all about them in a fun SciShow compilation all about the world of parasites!

SciShow is on TikTok! Check us out at www.tiktok.com/@scishow
----------
Support SciShow by becoming a patron on Patreon: www.patreon.com/scishow
----------
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:

Chris Peters, Matt Curls, Kevin Bealer, Jeffrey Mckishen, Jacob, Christopher R Boucher, Nazara, charles george, Christoph Schwanke, Ash, Silas Emrys, Eric Jensen, Adam, Brainard, Piya Shedden, Alex Hackman, James Knight, GrowingViolet, Sam Lutfi, Alisa Sherbow, Jason A Saslow, Dr. Melvin Sanicas, Melida Williams

----------
Looking for SciShow elsewhere on the internet?
SciShow Tangents Podcast: www.scishowtangents.org/
Facebook: www.facebook.com/scishow
Twitter: www.twitter.com/scishow
Instagram: instagram.com/thescishow
----------
Original Episodes:
Human Parasites -    • Terrifying Parasites Inside the Human...  
Brood Parasites -    • Brood Parasites  
Mind-controlling Parasites! -    • Mind-controlling Parasites!  
Toxoplasmosis: How Parasites in Your Cat Can Infect Your Brain -    • Toxoplasmosis: How Parasites in Your ...  
Why Don't Humans Get Heartworm? (Spoiler: We Do) -    • Why Don't Humans Get Heartworm? (Spoi...  
Why You Might Want Parasitic Worms -    • Why You Might Want Parasitic Worms  

All Comments (21)
  • @listennui
    No sir, this tapeworm is my antihistamine support animal
  • @stkygrnz
    Just seeing 2012 Hank shows that the man was made for being a presenter. He is so natural at it. His little tics and speaking style haven't changed at all over the years.
  • @SerunaXI
    Worst part of dealing with bedbugs is you are paranoid even years after you are free of them. Lord, there are days I still wanna prepare the vacuum and flip the mattress up just to do a sweep.
  • @joshuasalem5022
    1:24 The “You are mostly bacteria” fact has since been corrected. You actually have about the same number of human cells and bacteria cells, but you get rid of most of that bacteria every time you defecate.
  • 58,484 fears. . . "Good news is very unlikely a fish will swim up your urethra!" . . . 58,483 fears.
  • @mistingwolf
    Oh, the worms part made me remember something very sad. I was watching a veterinarian show and owners came in with a very lethargic bearded dragon. Owners of any animal, be sure to get your pet checked regularly for parasites! (something gross follows) . . . . The poor thing had so many worms in it that when the animal was sedated for examination, they started crawling out of its windpipe. Yeah, that animal did not make it.
  • @renkio
    Since toxoplasma gondii infection correlates with an increase risk of depression and self-harm in humans, might it not cause the same in rats? So maybe infected rats become suicidal. It's not that they're suddenly cat-loving; they're probably like "just take me I don't care anymore".
  • Hank: Worms, don’t google it. It’s gross 🤢 Me: Well…. Studying healthcare in tropical zone makes that inevitable for me 🤣🤣🤣🤣
  • @yamushu725
    Hank's little laugh as he goes, "We're our little biome!" that was rlly adorable ( 1:54 )
  • @SuLokify
    Parasites are evolutionary wizards. Their relationship with their hosts create a beautifully elliptical fitness back-and-forth.
  • @alphatonic1481
    When i hear about helpful worms i have to think about that one Futurama episode where Fry got worms by eating a black tomato slice thinking he ate a chocolate cookie. The worms he got from it made him 100% healthy and even helped him grow some muscles. Back then i wanted those worms too.
  • @hannah2818
    At my last job my boss started getting colonics and was convinced she had parasites that would need multiple colonics… could you do an episode talking about the pseudoscience that goes into colonics and misdiagnosing normal changes in our poop as parasites?
  • @ehjones
    It's worth pointing out about toxoplasmosis that the eggs shed in the faeces don't become infective for 1-5 days so fresh faeces isn't infective. It's microscopic faecal residue that might get on your cats paws and then gets shed wherever the cat goes that's infective. Clean out the litter tray promptly, and wash your hands regularly, especially after gardening or playing outside.
  • @stevie-ray2020
    Just accept that you're the host, & you have one helluva party inside!
  • @laanaalove
    I have what I suspect to potentially be delusional parasitosis (or perhaps some form of parasite related health anxiety/ ocd) yet I find myself endlessly consuming like university level parasitology material bc I tell myself that knowledge is power (I should seriously stop) but thank you for the trigger warning ❤
  • @Annathroy
    There really aren't ten times more bacteria cells than you cells in, well, you. This has been disproved times and times again. The original cited research was based on mostly guts (and bacteria in guts) where the 10-1 ratio might very well be true, however in general its more like 50-50
  • @EdsonR13
    So that Greys anatomy episode with the guy infecting himself with worms to treat his asthma was actually rooted in some real science
  • Interesting tidbit I learned in bio class: in areas where botflies are common, cuckoo eggs don't have to be so similar to the host bird eggs. The reason is that cuckoo chicks really love botfly larvae, so they keep their stepsiblings from getting blinded by botflies. So the host parents have an incentive to keep them around. Of course, it's not a conscious choice, just instinct.