Porcupines are covered in quills – about 30,000 on average. The quills cover most of their bodies except for their face and stomach. When a porcupine feels threatened, it rustles its quills. It makes a rattling sound, which warns others to back off. When a porcupine raises its quills, it also produces an odor. Porcupines scare off others by sound and noise.
Identify the concluding sentence.
Porcupines scare off others by sound and noise.