It sounds like a really bad horror movie, doesn’t it? While this creature has an ordinary brain inside its skull, it also has a second brain–much smaller, but still fully functioning– squishing around inside its belly. While the skull-brain thinks, and controls the body, and goes about its brainy business, the gut-brain also thinks, and processes information, and exerts control over the body too. It would probably make a pretty cheesy horror movie–but the thing is, it’s true. In fact, that creature with the extra brain is you. We’re talking about what scientists call the “enteric nervous system,” and all vertebrates have one, including humans. This is a collection of about a hundred million nerve cells that are wrapped around your stomach, esophagus, and intestines.