Interesting facts about reptiles

• Many kinds of reptiles molt (shed their skin) several times a year. The skin loosens after new scales form under it. The skin of lizards comes off in large strips.

• Lizards and snakes have a single sheet of overlapping scales. Other reptiles grow plates (separate areas of scales). The main function of the skin is to keep water in the animal's body. Reptiles can go without water for long periods, and many species thrive in deserts.

• The shape of a reptile's pupil indicates whether the animal is active at night or during the day. Most reptiles active at night have slitlike pupils that can be closed almost completely in bright light. Reptiles active in daytime have round pupils. Most reptiles have good vision, and some can tell the difference among colors.

• Only a few species of reptiles provide care for their eggs or young. Among pythons, mud snakes, and some skinks, the female wraps her body around the eggs and protects them. A female alligator carries her newly hatched young to water in her mouth.

• Snakes lack a middle ear and cannot hear most sounds carried through the air. They "hear" by sensing vibrations from the ground.

• A blindworm is not blind, nor is it a worm. It looks like a snake, but it is easily identified as a lizard because of its movable eyelids and fragile tail.

• Chameleons are known for their ability to change color, but many other kinds of lizards also have this ability. The chameleon's color is controlled by body chemicals called hormones, which affect pigments in the skin.

• Reptiles can go without food for long periods. After a snake eats a large meal, it might not feed again for several weeks.

• If a gecko is attacked, it can distract an enemy by waving its tail. When the enemy attacks the tail, the tail breaks off but keeps wriggling. While the enemy holds the tail, the gecko runs away. It soon grows a new tail.

• About 15 percent of all snake species have venom that is harmful or fatal to human beings. About 25 species cause most of the deaths from snakebites.

• Most snakes swallow their prey alive. However, poisonous snakes generally wait for their venom to kill an animal before they swallow it.

• About a fifth of all species of snakes bear live young. The pregnancy period among most of these species lasts about two or three months. Some species have more than 100 young at a time, but most bear far fewer.

• Tuataras are the only living members of an ancient group of reptiles that appeared on Earth more than 200 million years ago.

• Scientists believe turtles live longer than any other backboned animal. Some box turtles and tortoises have lived more than 100 years.

• Dinosaurs, the most spectacular reptiles, dominated land animals for millions of years. These creatures died out about 65 million years ago. The Diplodocus, a plant-eating dinosaur that measured about 90 feet (27 meters) long, was one of the largest animals that ever lived.

• Reptiles are cold-blooded—that is, their body temperature rarely differs much from the temperature of their surroundings. Reptiles that are active on hot, sunny days cool off by moving to shady spots.