A polar bear's thick fur, which protects it from the cold, is an example of a physical adaptation. Invite students to review the adaptations discussed earlier and identify each as either behavioral or physical. Ask students to brainstorm about reptiles, noting their responses on the chalkboard. Explain to the class that reptiles have been living on Earth for over 300 million years. They've been able to survive because of specific traits, both physical and behavioral, that enable them to live in their environments.
Lizards have great vision and use their tongues to taste their surroundings.
Crocodiles lose their teeth chomping on prey, but new sets always grow in. Snakes can go a long time without eating, but when they do, their meal is usually another animal. The tuatara is similar to a lizard, but the tuatara has a third eye and an extra row of teeth. Divide the class into groups of two or three students. You might allow them to select a different reptile of their own choice.