Why does nat want his wife to know how he feels bout the birds attacking?

Nat wants his wife to remain calm and not worry about the birds attacking because he believes that if she understands the severity of the situation, it will only increase her fear and anxiety. He feels a sense of responsibility to protect her from unnecessary distress, even if it means concealing the full extent of his own fears. Additionally, he may hope that by downplaying the threat, he can maintain a sense of normalcy for their family during a chaotic time.