Torvald Helmer's first two lines actually include two different nicknames for his wife, Nora. He first asks, from another room, "Is that my lark twittering there?" Nora responds that it is she that he hears. Next he asks, "When did the squirrel get home?" Just a bit later, while they discuss money, Nora asks if they can't be a little extravagant, seeing as how it is nearing Christmas and Torvald is getting a big promotion, and pay raise, at work soon. At this point, he calls her his "little featherbrain." Still on the topic of money, Torvald says of Nora, "It's a sweet little lark, but it gets through a lot of money. No one would believe how much it costs a man to keep such a little bird as you." He goes on to call her his "sweet little song-bird." As the play progresses, Torvald most frequently returns to calling Nora squirrel and lark, even as he adds "mad-cap" and "dove" and "child." What is most interesting about these nicknames is that Torvald so often refers to Nora as a wild animal, something untamed and free, even if diminutive. It contrasts sharply and ironically with how tamed and confined Nora has lived as a daughter and now as a wife and mother.