The monsters are Reapers, breaking down humans into base components for study. Just a smaller scale.
The creatures "eat" their victims in the same way the giant spider does in The Giant Spider Invasion. At least these creatures don't eat victims with their butt.
Money, Dear Boy: This movie's only reason for existing. Movie director Arthur Nelson (Vic Savage) was a known con-man, and funded the film by promising investors small parts in the movie. Facing several lawsuits as a result, Nelson pocketed the money and fled California.
Narm Charm: Bobby's granddad is so rotund, watching him try to walk up a slight incline comes off as hilarious.
Crow: Uh-Oh, here comes the most challenging scene in this movie.
Troubled Production: The original monster design was allegedly lost, the original soundtrack to the movie was lost (Or simply never recorded. A debunked rumor was that it was lost in Lake Tahoe), there were arguments between Allan Silliphant and Vic Savage over the direction of the film, and Savage himself being sued for fraud before the film's release!