Animal Kingdom Review Puzzle Animal Kingdom Review Puzzle Across 3. Body temperature fluctuates/changes with the environment. 4. Internal control of natural cycles tell animals when to migrate and gather food. 6. Class of vertebrates that have hair/fur and produce milk for their young. 8. Largest phylum of invertebrates that includes insects, arachnids and crustaceans. 11. Class of vertebrates that breathe through gills and live in water. 13. Behavior that comes naturally; insinct. 15. Phylum of invertebrates that have bilateral symmetry and includes tapeworms. 16. Most simple group of invertebrates that are asymmetrical. 17. Phylum of invertebrates with spiny skin that includes sea stars and sand dollars. 19. Animals with a skull and backbone. 20. Animals use this to attract mates; examples include showing off tail feathers or bird songs. 21. Behavior that includes hibernation, migration and estivation. Down 1. Phylum of invertebrates with radial symmetry and stinging tentacles. 2. Class of vertebrates with dry, scaly skin that are ectotherms (cold blooded). 5. Phylum of animals with backbones. 7. Class of vertebrates that have thin, moist skin and live near water. 9. Protective/hard outer covering. 10. Animals without a backbone. 12. Maintain a constant body temperature. 14. Internal skeleton for support. 18. Phylum of invertebrates typically with a hard shell covering soft bodies (clams and oysters).