Gecko feet aren't covered in suction cups or Velcro. They don’t squirt glue, or leave any footprints. Their secret is a herculean amount of grip -- at the atomic scale. A gecko’s toes are covered in tiny hairs that branch out into millions of microscopic, spatula-shaped pads. Those pads, called spatulae, get so close to the surfaces on which a gecko moves, the electrons of the spatulae and those on the surface start to sync up. That dance is called Van der Waals force, and it’s what gives geckos their sticking power.