Quiz

The set used for the Parmiter home, (where Joanna Miles's character has her head set ablaze by a "bug"), was the same set at Paramount Studios in Hollywood as the one used for the interiors of the Brady home in the ABC television series, La famiglia Brady (1969). Due to very poor ratings, being massacred by Sanford and Son (1972), the series had been canceled in 1974, a few months before filming on this film began. Since this film's release in 1975, "The Brady Bunch" became a ubiquitous hit in syndication, and the set has become easily recognizable to several generations of classic TV watchers, even though the set was altered for use in this film.

According to producer William Castle, director Jeannot Szwarc approached him with a problem; Joanna Miles was "deathy afraid" of cockroaches and obviously didn't want them crawling on her. When Castle tried to demonstrate how harmless they were by having one crawl on his own arm, he was bitten.

William Castle wanted as a "gimmick" to install brushes near the seats that would rub against theater patrons legs to simulate bugs crawling but it was turned down.

This was the last film William Castle worked on.

Most of the cockroach models used in this production were made by Karoly Fogassy, whose day job was a Technical Illustrator at the University of California at Riverside. For years afterward, visitors to his studio on campus were treated to the stares of the creepy bugs.