Discover Reading Level 3 Nonfiction Reader Learn all about turtles and tortoises in this nonfiction reader. Students will develop vocabulary and understanding of the life cycle of turtles and tortoises and learn the difference between the two types of animals. Sample Text: Tortoises use their claws to dig burrows that can be up to 30 feet long. Since they are cold-blooded and take on the temperature of their environment, they are hot when it's hot and cold when it's cold. To help control their temperature, they build south-facing burrows to stay warm and north-facing burrows to stay cool. Tortoises are very slow-moving animals. They usually move at less than 1/4 mph. The fastest they've been recorded moving is 5 mph.