By Elizabeth Landau, CNN
Zombies are everywhere, from hit TV shows like "The Walking Dead" to films like the upcoming "Warm Bodies." We seem fascinated by these ghastly creatures who are infected with an unknown disease that compels them to gurgle or groan and lust after brains.
These zombies are, of course, fictional. But the idea that a parasite can infect and control animals is real. There are several examples in nature where parasites manipulate host behavior to further their own reproductive goals. It's fascinating to think about how, when one organism invades another, the host can lose power over its own movements and behaviors.
David Hughes, assistant professor of entomology and biology at Pennsylvania State University, studies real-life zombie scenarios among ants.