Geckos are small to moderately large lizards belonging to the family Gekkonidae. These lizards are found in warm climates throughout the world. Geckos are unique among lizards in their vocalizations, making chirping sounds in social interactions with other geckos.
Geckos are unusual in other respects as well. Many species have specialized toe pads that enable them to climb smooth vertical surfaces and even cross indoor ceilings with ease. These antics are well-known to persons living in warm regions of the world where several species of geckos make their home inside human habitations. These species (such as the House gecko) become part of the indoor menagerie and are seldom really discouraged because they feed on insect pests.
Most geckos are tan to dark grey, subtly patterned, and somewhat rubbery looking. Some species can change color to blend in with their surroundings. However others can be brightly colored. Like most lizards, they eat insects. Some species are parthenogenic; the females are capable of reproducing without the aid of a male. This improves the gecko’s ability to spread to new islands.
The toes of the gecko have attracted a lot of attention, as they adhere to a wide variety of surfaces, without the use of liquids or surface tension. Recent studies of the setae on gecko footpads demonstrates that the attractive forces that hold geckos to surfaces are van der Waals interactions between the finely divided setae and the surfaces themselves.
That these kinds of interactions involve no liquids (or no gases) is important; in theory, a boot made of synthetic setae would adhere as easily to the surface of the International Space Station as it would to a living room wall.
Many gecko species may be kept as pets and will eat various kinds of insects.