Behavioral alterations upon environmental changes emerging from neuronal circuits are essential for survival. Many nematode species including the free-living nematode C. elegans exhibit an evolutionarily conserved, developmental stage-specific behavior called nictation: standing and waving in three-dimensional loops on a projection. We demonstrated that nictation is required for transmission of C. elegans to a new niche using flies as carriers, suggesting a role of nictation as a dispersal and survival strategy under harsh conditions. We found that cholinergic transmission in IL2 ciliated head neurons was both necessary and sufficient for the initiation of nictation. Now we have established signaling pathways and genes that are involved in this stage-specific behavior. We are also searching for the environmental stimuli that can activate IL2 neurons and what is(are) the downstream target cell(s) of IL2 neurons in the neural circuit by use of neural imaging. I will present other topics under study in the lab.