Geckos are the most species-rich group of lizards, with about 1,500 different species worldwide.

Most lizards have eyelids, just like humans, that clean and protect their eyes when they blink--but not geckos. Without eyelids, geckos can't blink--so they lick their eyeballs when they need to clean them.

Unlike other lizards, geckos have vocal cords, which allow them to make a variety of sounds, including barks, chirps, and clicks.

Geckos can stick to surfaces because their bulbous toes are covered in hundreds of tiny microscopic hairs called setae. Each seta splits off into hundreds of even smaller bristles called spatulae, which get so close to the contours in walls and ceilings that the van der Waals force kicks in. This type of physical bond happens when electrons from the gecko hair molecules and electrons from the wall molecules interact with each other and create an electromagnetic attraction.

The only surface that geckos can't stick to is Teflon. Well, dry Teflon. Add water, and geckos can stick even to this seemingly impossible surface.

Geckos have excellent night vision. Their color vision in low light is 350 times more sensitive than human color vision.

Geckos are polyphyodonts and able to replace each of their 100 teeth every 3 to 4 months. Next to the full grown tooth there is always a small replacement tooth developing from the odontogenic stem cell in the dental lamina.

In the wild, geckos detach their tails when grabbed by a predator. The severed tail wriggles rapidly, distracting the predator long enough for the gecko to escape. Fortunately, they are able to grow a new tail within 30 days--faster than any other type of lizard.

The Jaragua dwarf gecko (Sphaerodactylus ariasae) measures just 16-18 mm (0.63-0.71 in) from snout to tail and can fit on the head of a dime.

Tokay Geckos are large, can consume a lot of prey, and thrive in man-made environments, so they are sometimes utilized for the control of insects such as cockroaches that are considered pests. In some East Asian countries, they are even attributed with supernatural powers and believed to be descended from dragons.