There are over 6,000 recognized species of lizards, including iguanas, chameleons, geckos, Gila monsters, monitors, and skinks.

Lizards do push-ups for a variety of reasons, but for males, it's mostly to show strength and get attention, especially when courting a lady lizard.

Although most species of glass lizards have no legs, their head shapes, movable eyelids, and external ear openings identify them as lizards, not snakes. A few species have very small, stub-like legs near their rear vents. These are vestigial organs, meaning they once served an evolved purpose but are no longer used.

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.

Lizards, like snakes, rub against objects to help remove their shed skin and then consume the shed skin for calcium and other nutrients.

Just like snakes, a lizard sticks out its tongue to catch scent particles in the air and then places those particles on the roof of its mouth, where there are special sensory cells. The lizard can use these scent "clues" to find food or a mate or to detect enemies.

Although the Gila monster (Heloderma suspectum) is venomous, it represents little threat to humans because of its sluggish nature. Nevertheless, it has acquired a fearsome reputation. In the Old West, pioneers believed a number of myths about the Gila monster, including that it was immortal, that it's breath was toxic, and that, if bitten by a Gila monster, it would not let go until sunset or until it heard thunder.

Contrary to popular belief, a chameleon changing its skin color doesn't necessarily mean the lizard is trying to camouflage itself. More often, this remarkable ability is used as a way of controlling body temperature--lightening skin to reflect light and cool down or darkening skin to absorb light and warm up. Another primary function of color change is social signaling: altering skin tone to communicate intentions to potential mates or rivals.

Chuckwallas are strongly associated with rock outcrops, lava flows, and boulder piles, and are well-known for their defensive behavior of inflating their bodies to wedge themselves in tight crevices.

Young Komodo dragons are vulnerable to cannibalism by adults, which get approximately 10 percent of their diet from consuming juveniles of their own species. As a result, juveniles spend the beginning of their lives living in trees. Their claws make them ideal climbers, but only when young--they become too heavy to climb trees as adults.