This horror movie about vampire bats was first released in the same year as a then major new version of 'Dracula' (1979) starring Frank Langella as the Count. That movie was one of five Dracula movies made and first released around 1979. The films are Dracula (1979), Nosferatu the Vampyre (1979), Love at First Bite (1979), Nocturna (1979), and Dracula Blows His Cool (1979). Also from 1979 were the vampire movies Thirst (1979) and Salem's Lot (1979).
The movie won Worst Picture at the Hastings Bad Cinema Society's 2nd Stinkers Bad Movie Awards in 1979.
Bracken Cave Preserve, where the real life bat footage was shot, is the largest bat colony in the world and home to over twenty million Mexican free-tailed bats (also known as the ''Tadarida brasiliensis'' species). The site is located less than twenty miles from San Antonio, Texas and is situated in the southern part of the state's Comal County.
The Texas filming location of Bracken Cave near San Antonio, which was used by documentary filmmaker David Saxon to shoot the real footage of real bats for the film, was the same site that he had used for his National Geographic television special on bats entitled 'Strange Creatures of the Night' (1973) (TV). This earlier program had been narrated by Leslie Nielsen who later starred as the title character in Mel Brook's vampire spoof 'Dracula: Dead and Loving It' (1995).
Columbia Picturres spent a sizable portion of the film's budget hiring Oscar winning special effects master Carlo Rambaldi (E.T. and the 1976 remake of King Kong) to create "believeable, terrifying bats," since they realized that would be the key to the film being a box office hit. What they got for their money were creatures that looked exactly like what they were - battery powered, rubber bats mounted on poles that were incapable of looking or moving anything like actual bats. As a result, the film proved to be a major disappointment.