Deadlier Than the Male intrigue when he comes to visit. The title is a reference to the 1911 Rudyard Kipling poem "The Female of the Species," which includes the line, "The female of the species must be deadlier than the male", and also refers to Sapper's earlier Drummond book, "The Female of the Species". The working title of the film was "The Female of the Species". "Deadlier Than the Male", the song featured in the film`s opening credit sequence, was performed by the Walker Brothers. Filmed in Technicolor and Techniscope, portions of the film were shot in Lerici, La Spezia, Liguria, Italy. A sequel,
Social groups in male and female prisons in the United States actions as purely physical to avoid homophobic bias against themselves. In the 1960s, Tittle observed that female inmates engaging in homosexual activity were more than five times more likely to describe their relationships as emotionally, rather than physically, based. Pseudo-families, also known as familial networks, are social groups of approximately 15 to 20 inmates formed in women's prisons which have been regularly observed by many anthropological and sociological researchers since the 1930s. Within the pseudo-family, inmates take on roles which parallel standard family roles, including parents, children, and siblings, as well as extended family such as aunt, uncle, or grandparent.