Geckos are lizards belonging to the infraorder Gekkota, found in warm climates throughout the world. They range from 1.6 cm to 60 cm. Geckos are unique among lizards in their vocalizations, making chirping sounds in social interactions with other geckos. Geckos are the second most species rich group of lizards (after skinks), with close to 1,500 different species worldwide and many others likely yet to be discovered.
All geckos, excluding the Eublepharidae family, have no eyelids and instead have a transparent membrane which they lick to clean. Many species will, in defense, expel a foul-smelling material and feces onto their aggressors. There are also many species that will drop their tails in defense, a process called autotomy. Many species are well known for their specialized toe pads that enable them to climb smooth and vertical surfaces, and even cross indoor ceilings with ease.