Them!

Them! is a 1954 black-and-white science fiction giant monster film starring James Whitmore, Edmund Gwenn, Joan Weldon, and James Arness. Produced by David Weisbart, the film was directed by Gordon Douglas, based on an original story by George Worthing Yates that was developed into a screenplay by Ted Sherdeman, with adaptation by Russell Hughes.

The film is one of the first of the 1950s "nuclear monster" movies, and the first with big bugs as the threat. A nest of gigantic irradiated ants is discovered in the New Mexico desert, and they quickly become a national threat when it is found that two young queens and their consorts have escaped to establish new colonies. The national search that follows culminates in a battle with the last surviving colony in the concrete spillways and storm drain system of Los Angeles.