We are all familiar with that uncomfortable feeling in our stomach when faced with a threatening situation. By studying rats, researchers have been able to prove for the first time that our ‘gut instinct’ has a significant impact on how we react to fear. An unlit, deserted car park at night, footsteps in the gloom. The heart beats faster and the stomach ties itself in knots. We often feel threatening situations in our stomachs. While the brain has long been viewed as the center of all emotions, researchers are increasingly trying to get to the bottom of this proverbial gut instinct.