Geckos are small to average sized lizards belonging to the family Gekkonidae, which comprises dozens of genera and several hundred different species found in warm climates throughout the world. Most geckos are arboreal (inhabiting or spending large amounts of time in trees or bushes) and nocturnal.
Geckos are unique among lizards in their vocalizations, making chirping sounds in social interactions with other geckos. The name stems from the Malay word gekoq, imitative of its cry. Geckos are unusual in other respects as well. Most geckos lack movable eyelids and instead have a transparent membrane that they lick to clean. Many species have specialized toe pads with microscopic, hairlike projections that enable them to climb smooth vertical surfaces and even cross indoor ceilings with ease. These antics are well-known to people who live in warm regions of the world where several species of geckos make their home inside human habitations. These species (for example the house gecko) become part of the indoor menagerie and are seldom really discouraged because they feed on insect pests.
The diverse color, patterns, and behaviors of geckos add to the wonder of nature for humans. Furthermore, just as many human inventions and innovations have been based on systems in creation, the gecko's unique method of walking on walls and even ceilings has lead to efforts to develop practical applications for this knowledge, such as boots for walking on surfaces in space.