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,
More Today Than Yesterday famous at the turn of the 20th century in a poem by Rosemonde Gérard, the wife of the poet and playwright Edmond Rostand ("Cyrano de Bergerac"). More Today Than Yesterday "More Today Than Yesterday" is a song written by Pat Upton and performed by Spiral Starecase. It reached number 6 in Canada, number 7 on the "Cashbox" Top 100, and number 12 on the "Billboard" Hot 100 in 1969. It was also released in the United Kingdom as a single, but did not chart. The song was featured on their 1969 album, "More Today Than Yesterday". Produced by Sonny Knight