WARNING! This episode will freak you out. Did you know that almost half of all life on earth is parasitic? Join us for an eerie video hosted by Hank Green and learn about four of the creepiest parasites on Earth.

Go to http://Brilliant.org/SciShow to try their Beautiful Geometry course. The first 200 subscribers get 20% off an annual Premium subscription.

Hosted by: Hank Green

SciShow has a spinoff podcast! It's called SciShow Tangents. Check it out at http://www.scishowtangents.org
----------
Support SciShow by becoming a patron on Patreon:   / scishow  
----------
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:

Adam Brainard, Greg, Alex Hackman, Sam Lutfi, D.A. Noe, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Charles Southerland, Patrick D. Ashmore, charles george, Kevin Bealer, Chris Peters
----------
Looking for SciShow elsewhere on the internet?
Facebook:   / scishow  
Twitter:   / scishow  
Tumblr:   / scishow  
Instagram:   / thescishow  
----------
Sources:
https://www.otago.ac.nz/parasitegroup...
https://www.researchgate.net/publicat...
https://repositories.lib.utexas.edu/h...
https://www.researchgate.net/profile/...
http://aquaticcommons.org/8583/1/NG_6...
https://www.researchgate.net/publicat...
http://people.oregonstate.edu/~blaust...
https://www.researchgate.net/publicat...
https://zslpublications.onlinelibrary...
https://www.sciencedirect.com/science...
https://nph.onlinelibrary.wiley.com/d...
https://www.harvardmagazine.com/2017/...
https://bulbapedia.bulbagarden.net/wi...)
https://www.ncbi.nlm.nih.gov/pmc/arti...


Image Sources:
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...

https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...

https://commons.wikimedia.org/wiki/Fi...
https://www.eurekalert.org/multimedia...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...

https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...
https://commons.wikimedia.org/wiki/Fi...