Mind control and zombification do exist. Just look at these crickets

Warning: this video is not for the squeamish.

Mayflies make a quick and nutritious snack for crickets. But, rather unfortunately for the cricket population of California, some mayflies are home to hairworms (nematomorphs) – parasitic creatures that will stop at nothing to make their way back to water. Once consumed, hairworms feed off crickets from the inside, absorbing all of their lipids, and eventually putting the cricket in a state of developmental and reproductive limbo. Worse still, once these fast-growing parasites reach their adult length of one to two feet, they zombify their hosts, unleashing brain chemicals that make the infected crickets wander aimlessly until they hit water, where the worms make their final escape and start the whole cycle anew. By studying this process, scientists hope to learn more about how brain parasites might affect human behaviour. The ordeal is captured in microscopic detail in this episode of the often creepy, always fascinating science documentary series Deep Look. Read more about the video at KQED Science.