Reaching high speed with tiny steps and the powerful "fifth" leg - ants

Locomotion scientists from the University of Jena analyze the locomotion of ants

They are small, fast and agile: Thanks to an extremely dynamic rear-wheel-drive and an efficient light-weight build, but mainly because of a an ingenious stabilizing system, the little runabouts manage to develop absolute top speed. We do not talk about a new generation of top-speed compact cars. We talk about wood ants (formica polyctena). The animals cover up to 26 body lengths per second and reach a frequency of 16 steps per second in doing so.

"And all of that without lifting off" says locomotion scientist Lars Reinhardt from the university Friedrich-Schiller-Universität in Jena. "Because in difference to most of the other fast running mammals or birds, there is no flight phase within the locomotion of ants." Also when running fast, according to Reinhardt, the animals never use soil contact, but they reach the high speed using tiny steps. This is the result the junior researcher from the team of Prof. Dr. Reinhard Blickhan reached in a recent study. According to his comment in the journal "The Journal of Experimental Biology", ants use a locomotion pattern called "grounded running" (DOI 10.1242/jeb.098426).

In the present work the researchers from Jena did the very first comprehensive, biomechanical locomotion analysis of ants, measuring and analyzing not only the motion processes but also the forces within the animals' locomotion. This only was possible with a specially developed, highly sensitive sensor, that Lars Reinhardt designed during his PhD thesis (DOI: 10.1242/jeb.094177). The sensor consists of elastic polymer strips that are able to capture even the smallest forces within the micro-Newton-area in all three directions in space.