Title: How Narwhals Work | HowStuffWorks
Headings: How Narwhals Work
How Narwhals Work
Meet the Narwhal
Narwhal Behavior
The Narwhal Tusk
Threats to Narwhals
Citation

Content: On the outside of the tooth, there's enamel, with hard materials called dentin and cementum below that. At the very center of the tooth is the pulp, where the blood and nerves are. ( You might realize you have a cavity once the pulp is infected and hurts.) The hard outer layers protect the sensitive inner layers of the tooth. Advertisement
A narwhal tusk is the exact opposite. The soft, sensitive part is on th