Fig. 7. The relationship between walking speed and (A) stride frequency, (B) (relative) stride length. The different experimental situations are colour-coded as in the previous figures: red, stilts; blue, normal; yellow, stumps I; green, stumps II. Linear regression lines are indicated. The regression lines for the normal ants: stride frequency=0.054xwalking speed+7.72 (R²=0.87) in A; stride length=0.018xwalking speed+6.80 (R²=0.81) in B (stride frequency = Hz, stride length = mm and walking speed = mm s^-1).