Figure 2. Behaviors expected to require spatial detection of stimuli. (A) Klinotaxis is the gradual biasing of the animals? gait in a preferred direction within a stimulus gradient (red).⁸ (B) During isothermal tracking, animals select a preferred temperature in a radial or linear (not shown) temperature gradient and continuously bias their gait to remain within a narrow stimulus band.^5-7 (C) When animals encounter an aversive boundary (red) at an oblique angle, they perform a short reversal and then reliably turn away from the boundary.⁹