Fig. 4.

(A and B) Growth rate of chains predicted by modeling simulations for several combinations of gap height (x-axis) and traffic flow (y-axis). The color of each square indicates the median growth rate of chains calculated from 100 simulations. Black regions indicate the absence of chain formation. White dots indicate the position on the graph of our behavioral experiments. Areas of equal growth rate are indicated by white dashed lines. The dashed green line indicates the level of traffic for which chain growth is nil. (A) Growth rate predicted by the distance-dependent model. (B) Growth rate predicted by the distance-independent model. Full range of simulations shown in SI Appendix, Fig. S7. (C) Growth in chain length as a function of time for experimental data (points) and model predictions (line) when the distance from the platform is kept constant. The red shaded area shows 95% confidence intervals of the modeling predictions.