- Large South American bats were imported for the picture.
- The actors all played their roles for a straight horror movie, unaware of the twist-ending until the last few days of shooting.
- Preview reviews list a running time of 80 minutes, so that considerable footage was cut prior to the film's release. This would account for many listed actors who were cut from the final print.
- The film was banned in Poland, and censors in Hungary excised the screams, shots of bats and other gruesome scenes.
- There was a remarkable degree of difficulty to shooting the scene where 'Carol Borland' flies like a bat. A jockey initially doubled for her but became nauseous on the wires. A bar was placed down the back of her dress running from her neck to her ankles, but it took some time for she and the handlers to get this right. The single shot took three weeks to work. (All of this for a scene where Borland is supposed to be an actor pretending to be flying).
Please support TCMDB by adding to this information.Click here to contribute