Fig. 1. The rapid impulsive perturbation (RIP) apparatus. (A) Diagram of the RIP apparatus, which consisted of a plastic cylinder placed laterally on a balsawood base. The apparatus was mounted on the mesonotum of the animal using small bolts. The cylinder was loaded with flint, black powder and a steel ball bearing. (B) The triggering system for generating RIPs. Flint and black powder were ignited using a spark generated from the ignition module, which was triggered manually.