Locomotion on legs, typical of the arthropods and most land vertebrates. The number of legs varies from two to more than a hundred (in some millipedes; Myriapoda). Two-legged animals tend to have large feet, to aid balance, or a large tail as in kangaroos (Macropodidae). During walking, there is always one foot on the ground, but both feet may leave the ground during running.
Walking is the slowest quadrupedal gait, and the most stable, because there are always three feet on the ground. All faster gaits have unstable phases, when there are two, one, or no feet on the ground.
Insects have six legs, which are generally moved in sets of three, to that the insect is always stable. Animals with more than six legs may have a variety of gaits and can readily maintain stability.
Subjects: Medicine and Health.