Across
- 5. humans use them to breathe
- 7. animals active at night
- 8. the only mammals that can fly
- 9. when baby amphibians change to adults
- 11. animals that have got a backbone
- 12. help mammals move in water
- 15. keeps birds warm
- 16. the skin of amphibians is wet
Down
- 1. sitting on eggs to help them grow
- 2. mammals that are oviparous
- 3. reptile that hasn't got a tail
- 4. baby frogs
- 6. subgroup that gives birth to live babies
- 10. adult amphibians breathe through it
- 13. it's a monotreme
- 14. it protects turtles' bodies
- 15. biggest group of vertebrates