The world is highly complex. To survive, animals extract information from environmental signals, evaluate it in the context of internal states, and transform it into motor actions for navigation. Chemical cues are essential and conserved across species, yet strategies and mechanisms remain poorly understood. This project proposes a novel approach using zebrafish larvae to address three aims: Aim1: What information in chemical stimuli guides navigation? Aim2: How are chemical stimuli encoded in the brain and which circuits represent spatial information? Aim3: How do internal states shape navigation strategies, and how do chemical stimuli affect these states at behavioral and neural levels? Zebrafish larvae enable the integration of microfluidics, light-sheet microscopy, optogenetics, and large-scale data analysis to study chemical-guided navigation with precise stimulus control while measuring whole-brain activity and behavior. In this poster, I hope to discuss with the general audience the central ideas of the project with which I am starting a laboratory at IFIByNE.