What does Little Tree learn from this experience with Granpa? Chapter12

As Little Tree digs in a fish hole by hand, he hears a whirring sound next to him. It's a rattlesnake, poised to strike! Granpa silently appears and tells him not to move a muscle. Suddenly, Granpa puts his hand between Little Tree's face and the snake's head, steady as a rock. The snake strikes fast, burying his fangs into Granpa's hand. Granpa uses his other hand to grab the rattler's head and choke it to death. Granpa cuts big slashes in his hand and sucks out the blood. His arm begins to swell and turn blue. Terrified, Little Tree runs to get Granma. Little Tree is emotionally distraught when he arrives; but Granma stays calm and gets the information she needs. She runs out of the cabin with a quickly packed sack, braids flying. Little Tree screams after her, "Don't let Granpa die!"