Researchers at the University of Bonn and the University of Cambridge have identified an important control circuit involved in the eating process. The study has revealed that fly larvae have special sensors, or receptors, in their esophagus that are triggered as soon as the animal swallows something. If the larva has swallowed food, they tell the brain to release serotonin. This messenger substance – which is often also referred to as the feel-good hormone – ensures that the larva continues to eat. The researchers assume that humans also have a very similar control circuit. The results were recently published in the journal “Current Biology.”