Example: Brain Parasites Parasites that turn victims into mindless, zombie-like slaves are fairly common in nature. There's one called toxoplasmosa gondii that seems to devote its entire existence to being terrifying.
This bug infects rats, but can only breed inside the intestines of a cat. The parasite knows it needs to get the rat inside the cat so the parasite takes over the rat's freaking brain, and intentionally makes it scurry toward where the cats hang out. The rat is being programmed to get itself eaten, and it doesn't even know.
Of course, those are just rats, right?
How it can result in zombies?
Hey, did we mention that half the human population on Earth is infected with toxoplasmosa, and don't know it? Hey, maybe you're one of them. Flip a coin.
Take a deep breath. Relax. It's a joke right? Well, take a look around your office. Could some of your co-workers be infected? How would you know? Have some of them been acting stranger than usual? It could even happen to our favorite office co-workers: