It was made and released in 1977.
Made maybe, but I've found that 1978 seems to be mentioned the most for it's release year.
People believe what they want to believe. One term for this is Faith. Another is Delusion.
I have found numerous different dates and titles for this as well. The version I saw was on the sci-fi invasion 50 movie pack were in the booklet it lists the date as 1978. I looked in a movie guidebook I had where this movie was listed as being made in 1983. Here on IMDB it says 1981. So I really don't know which one is correct. Also when the movie comes on on the DVD version that I had the title simply says prey but it is listed in the booklet as alien prey.share
This film was available on video back in 1981 because I remember missing it after I fell asleep while everyone else watched it!
Shut the door, Mary...