How do geckos stick upside down?

 Geckos has the ability to scale smooth surfaces​—even skittering across a smooth ceiling—​without slipping! How does this amazing little lizard do it?

Geckos can stick to surfaces because their bulbous toes are covered in hundreds of tiny microscopic hairs called setae.Each seta splits off into hundreds of even smaller bristles called spatulae. Scientists already knew that the tufts of tiny hairs get so close to the contours in walls and ceilings that the vander-waals force.

Each toe of the gecko contains ridges that have thousands of hairlike protrusions. Each protrusion, in turn, has hundreds of microscopic filament  s. The intermolecular forces (called van der Waals forces) that emanate from these filaments are sufficient to hold the lizard’s weight​—even when it is scurrying upside down along a glass surface!