Methinks this song is about Shakira, who had a boyfriend that wouldn’t let her do anything, and she just needed to do something, because she had a wild instinct, and she was mad, cause all she ever did was care for him, and he didn’t even thank her. She is turning into a werewolf, and the boy doesn’t believe her. In the second one she’s saying that she’s nocturnal and she not going to have mercy.