View full lesson: http://ed.ted.com/lessons/how-parasites-change-their-host-s-behavior-jaap-de-roode The biggest challenge in a parasite’s life is to move from one host to another. Intriguingly, many parasites have evolved the ability to manipulate the behavior of their hosts to improve their own survival -- sometimes even by direct brain control. Jaap de Roode details a few parasites that can really mess with the mind. Lesson by Jaap de Roode, animation by Andrew Foerster.