Vertebrates are animals with a backbone, including groups such as mammals, birds, reptiles, amphibians, and fish. Articles are a unique way for readers to learn about the world around them. In addition to building reading comprehension skills and increasing vocabulary, articles can be used for writing and research. The article is broken into 5 single-page sections: What Is, Warm-Blooded Vertebrates, Cold-Blooded Vertebrates, Fun Facts, and Words to Know.