gecko

Any lizard of the family Gekkonidae. Geckos are common worldwide in warm climates, and have large heads and short, stout bodies. Many have no eyelids. They are able to climb vertically and walk upside down on smooth surfaces in their search for flies, spiders, and other prey.

There are about 850 known species of gecko. There are 102 Australian species, 17 new species having been discovered there 1986–96. A new species of gecko Tarentola mindiae was identified in Egypt's Western Desert in 1997. In June 2000 US researchers explained the mechanism whereby geckos are able to walk across ceilings and up walls. Each foot is covered with nearly 5,000 tiny hairs less than a tenth of the diameter of human hair, called setae. Each seta is tipped with hundreds of spatula-shaped structures. The setae generate a force of over 10 kg/22 lb when clinging on, by force of attraction between molecules (explained by van der Waals' law).