Geckos are part of a large genus known as gekkoninae which consists of more than 2,000 different species. These lizards are small to medium-sized and can be widely varied in appearance. Most species of gecko have several physical similarities as well as common behavioral traits. Numerous gecko species are also commonly kept as exotic pets.Geckos are a wide-ranging group of reptiles. Some of them are slender-bodied, while others are more robust. The size range between the smallest and largest gecko species is noticeable. The larger species grows to more than a foot, while the smallest species, such as the dwarf gecko, grows to just over 1/2 inch and can fit on a quarter. Gecko toes always have circular pads which have small hairs on the underside that help them climb even the smoothest surfaces. Their eyes are often large and round compared to most lizards and their ears are visible as small holes on the sides of the head. Their skin is scaly and can come in a multitude of bright or more bland coloration, depending on the species.Geckos can be found all around the globe, but are most common around equatorial regions. Being small and cold blooded, geckos are only found in the warmest areas of the world within a range of habitat types. Climbing skills mean that many species are at home in tropical rain forests as well as dry, arid deserts, mountainous regions and open grasslands. Some species are even more adaptable and can be found living in urban gardens and in some cases inside houses.ll geckos are carnivores and actively hunt for food. Smaller species feed most commonly on insects, worms and spiders. Larger geckos can tackle more complex prey such as small birds, other reptiles and mammals such as mice. Some geckos can be fierce in self defense against predators or even detach their tails when attacked in order to distract the predator while they escape. Since they are generally small lizards, a wide variety of wild and domestic animals will readily feed on them. Large snakes, lizards, birds of prey and predatory mammals all pose a threat to geckos.Geckos are all solitary animals and do not live in any kind of group. The lizards come together during the mating season which varies by species and geographic range. Fertilization is always internal and small numbers of soft eggs are laid which later harden to protect the embryo. In some species males and females will protect the eggs until they hatch, while others will leave the eggs never to return. Beyond hatching, generally no further parental protection is offered. The age of sexual maturity, pregnancy length and incubation periods all vary depending on the species.