Robotic snake moves by pushing off obstacles

A new creature slithering out of the Norwegian University of
Science and Technology is noticeably different than most. As you can
see above, there's a distinct lack of treads, tracks or wheels on Aiko,
as it actually pushes off foreign objects it encounters in order to
creep forward. Additionally, researchers have created a "virtual
double" of the critter in order to help guide the development of the
actual robot.
Article Link (Gizmodo)