(A-D) Schematic of salt chemotaxis plasticity in C. elegans. After animals were conditioned on agar plates at high or low salt concentrations in the absence of food for six hours, they avoid the salt concentrations experienced under starvation (A, B). After animals were conditioned on agar plates at high or low salt concentrations in the presence of bacterial food, they migrate toward the salt concentrations encountered during feeding (C, D). (E-H) Salt chemotaxis of wild-type and daf-16 mutant animals after conditioning with high- (E, G) or low-salt (F, H) in the absence (E, F) or presence (G, H) of food. Each dot in red or blue represents a chemotaxis index obtained from each trial when animals were conditioned at a high or low concentration of salt, respectively. Error bars indicate SEM. ANOVA with Dunnett’s test compared to wild type, ***p < 0.001. (E, F) N = 11. (G, H) N = 7.