Reptiles are vertebrates, or animals with backbones. Their bodies are dry and covered with scales . The scales may be tiny, large, smooth, bony, or spiny. Reptiles are also cold-blooded. Their body temperature depends on the temperature of their environment . If a reptile is too hot, it must move to the shade. If it needs warmth, it must get into the sun. Most reptiles lay eggs. But a few species give birth to live young. 9