Get perks and exclusive access to TED-Ed by supporting our mission of free worldwide education for all: https://www.patreon.com/teded -- Nearly 350 species of fish have specialized anatomical structures that generate and detect electrical signals. Underwater, where light is scarce, electrical signals offer ways to communicate, navigate, find, and sometimes stun prey. But how do these fish produce electricity? And why? Eleanor Nelsen illuminates the science behind electric fish. Lesson by Eleanor Nelsen, directed by TOTEM Studio. Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Support us on Patreon: http://bit.ly/TEDEdPatreon Follow us on Facebook: http://bit.ly/TEDEdFacebook Find us on Twitter: http://bit.ly/TEDEdTwitter Peep us on Instagram: http://bit.ly/TEDEdInstagram View full lesson: https://ed.ted.com/lessons/how-do-fish-make-electricity-eleanor-nelsen Thank you so much to our patrons for your support! Without you this video would not be possible! Amber Wood, Ophelia Gibson Best, Cas Jamieson, Phyllis Dubrow, Michelle Stevens-Stanford, Aliyya Rachmadi, Eunsun Kim, Samantha Chow, Philippe Spoden, Mark Sasse II, Ayala Ron, Armando Ello, Manognya Chakrapani, Doreen Reynolds-Consolati, Simon Holst Ravn, Rakshit Kothari, Melissa Sorrells, Antony Lee, Husain Mohammad, Dino Hrnjić, Côme Vincent, Daniel Mardale, Alessandra Tasso, Zhufeng Wang, Astia Rizki Safitri.