 Several of the trained rats featured in the film would later be used in the 1971 horror film "Willard" and its 1972 sequel "Ben".During the course of filming, tensions between the town locals and the film's cast and crew mounted because of the locals' uncertainty and misunderstandings with the film's director.After one incident in which the locals witnessed Durston attempting to motivate actress Iris Brooks for an emotional scene, they contacted the town sheriff, insisting that Durston was abusing the cast and crew and should be arrested or replaced with another director.