wolves warn other wolves by using different what?
backbones parties hormones colors expression antigens several pitches
A B C D E F G H
Wolves communicate with each other using the different pitches of their howl.
wolves warn other wolves by using different pitches
wolves warn other wolves by using different what? (A) backbones (B) parties (C) hormones (D) colors (E) expression (F) antigens (G) several (H) pitches