A reviewer for "Publishers Weekly" noted that friendship and responsibility are taught to characters in the novels, while another reviewer pointed out the idea that, just as Clan cats shun house cats for their soft life, people should realize that it is necessary to experience hardship in life. A Storysnoops reviewer noted that one of the themes was that "it doesn't matter where you come from, only who you are inside". In "Dawn", the importance of cooperation is explored. The four Clans, normally hostile to each other, are forced to work together in order to find a new home. Other themes that have been pointed out deal with family, loss, honor, bravery, death, loyalty, and following rules.