When startled, do all fish respond the same way? A few fish, like Mexican cavefish, have evolved in unique environments without any predators. To see how this lack of predation impacts escape responses that are highly stereotyped across fish species, scientists explored this tiny fish to determine if there are evolved differences in them. Findings reveal that the dramatic ecological differences between cave and river environments contribute to differences in escape behavior in blind cavefish and river-dwelling surface cavefish.