Serotonin depresses feeding behaviour in ants

► Serotonin (5-HT) depresses sucrose feeding in Camponotus mus ants. ► Intake rate decreases in a dose-dependent manner. ► This occurs by a diminution in the volume of solution taken per pump contraction. ► Oesophagus, crop and proventriculus present 5-HT innervation but sucking-pump does not. ► Frontal and suboesophageal ganglions contain 5-HT immunoreactive cell bodies.