REASONS MY DOG GROWLS

My puppy doesn't understand why he has the ability to growl.
  1. 1.
    He hears a noise.
  2. 2.
    He sees a child outside.
  3. 3.
    He wants to go outside.
  4. 4.
    He's hungry.
  5. 5.
    He wants me to throw the ball.
  6. 6.
    He's playing with another dog.
  7. 7.
    FOR NO REASON AT ALL.