Reaching high speed with tiny steps and the powerful "fifth" leg - ants part 2

 ants part 2

The step pattern of ants, as Lars Reinhardt explains, remains the same at any speed: Three legs each of the altogether three leg pairs touch the soil. "The animals use the so-called alternating tripod-gait." They synchronically move the front and the hind leg of one side and the middle leg of the opposite side forward. Only when all three have soil contact again, the corresponding other three legs lift off. He claims that this is very energy-consuming. "But this way the ants get a very stable gait, also in rough areas," Reinhardt says. This also enables very fast changes of direction. "And this is more important for outdoor survival than saving energy."

The main drive for the forward movement of the ants is done by the hind leg pair, according to a further result of the latest study, while the front legs have more of a breaking effect and the legs in the body center contribute to the stabilization of the gait.

The motion researchers also found out that the ants briefly touch the soil between the steps with the hindquarters in regular intervals, also slightly slowing down the locomotion. "This way they put down odor trails indicating the way for their conspecifics," Reinhardt explains. This hampers on the one hand locomotion of the individual animal, on the other hand the ants also benefit from an established "road".

Credit: M. Großmann_pixelio.de

 

Original publications:
Reinhardt L, Blickhan R. Level locomotion in wood ants: evidence for grounded running, The Journal of Experimental Biology (2014) 217, 2358-2370, DOI: 10.1242/jeb.098426
Reinhardt L, Blickhan R. Ultra-miniature force plate for measuring triaxial forces in the micronewton range, The Journal of Experimental Biology (2014) 217, 704-710, DOI: 10.1242/jeb.094177