Labor is seen throughout the novel as the children are forced to dig holes while at Camp Green Lake. This theme is unusual in children's literature as many authors portray children as carefree and without responsibility. If they do engage in work, it is synonymous with play. Critic Maria Nikolajeva contends that Holes is set apart through the not just manual, but forced labor Stanley and the other campers do daily. This is first referenced at the beginning of the book when the purpose of the camp is stated: "If you take a bad boy and make him dig a hole every day in the hot sun, it will turn him into a good boy".