To examine a gecko's cling, [study leader Alyssa] Stark and colleagues put harnesses on six tokay geckos (Gekko gecko) and put them on four surfaces which varied in their wettability, or their degree of water resistance.

The reptiles' feet were submerged in water on glass, plexiglass, a transparent plastic often used as a glass alternative, and Teflon.

Plexiglass and the transparent plastic "mimic the surface chemistry of the leaves geckos are really walking on in their natural environments," Stark said.

As a gecko moved across each surface, the team applied a force in the opposite direction until the animal slipped, which allowed them to measure the animal's grip.

The results showed that on glass, a film of water developed between the geckos' toes and the surface, reducing their ability to stick to the glass. But on plexiglass and the plastic, the geckos' toes create air pockets that allows their feet to stay dry—preserving the stickiness.