The Rattrap deals with the issues of human loneliness and the need to bond with others. Not only the peddler but also other characters like the crofter, the ironmaster and Edla emphasise this fact.
The peddler's conscience had left him because he had been lonely in his predicament, for a long time. But Edla's kindness and hospitality changed him. The crofter, on the other hand, is a lonely fellow whose craving for company leads him to give shelter to a vagabond, and he ends up getting robbed. Even, the ironmaster and his daughter suffer from loneliness. They crave company on Christmas Eve and are excited when they get the opportunity to serve a guest.