Starring Marjoe Gortner, Pamela Franklin, Ralph Meeker, Jon Cypher, and Ida Lupino, the film was loosely based on a portion of the 1904 H. G. Wells novel The Food of the Gods and How It Came to Earth.

A professional football player named Morgan is on the island for a hunting trip with his buddies when one of them is stung to death by giant wasps.

Morgan blows up a nearby dam, flooding the area and drowning the rats, whose size and weight render them unable to swim.

The substance is consumed by dairy cows, and in the film's closing scene, schoolchildren are shown unwittingly drinking the tainted milk, implying that they will also experience abnormal growth.

Wells' novella The Food of the Gods and How It Came to Earth (1904) in 1965 and hired Bert I. Gordon to direct and produce a partial adaptation of it as Village of the Giants (1965) at his studio Embassy Pictures.

[8] Vincent Canby of The New York Times called the film "a stunningly ridiculous mixture of science-fiction and horror-film clichés.

"[9] Gene Siskel of the Chicago Tribune gave the film half of one star out of four and wrote, "The heavy television ad campaign promises six-foot roosters and panther-sized rats.

"[10] Arthur D. Murphy of Variety wrote, "Too much emphasis by Gordon on his good special visual effects combines with too little attention to his writing chores ... Every player has done better before; this script is atrocious.

"[12] Tom Milne of The Monthly Film Bulletin called it "A truly appalling piece of s-f horror in which the cretinous dialogue, hopefully illuminating the follies of human greed and tampering with nature, poses more of a hazard to the cast than the crudely animated giant wasps or the monster rat and cockerel heads stiffly manipulated from the wings.