Them

Sgt. Ben Peterson and his partner Ed Blackburn patrol the desert near Alamogordo when they encounter a young girl wandering aimlessly. The girl is found in a catatonic state near a damaged caravan, raising immediate concerns about her safety and the fate of those who may have been with her.

Authorities are summoned to the scene, and an ambulance is called for the girl. At first unresponsive, she is suddenly roused by a high-pitched hum from the ground, her eyes wide open, but collapses again as the sound fades, leaving the adults bewildered.

Later that night, while checking a rural general store, Peterson discovers the owner has been murdered. Shaken by the chilling scene, he attempts to secure the area, only to realize that his partner Blackburn has mysteriously vanished without a trace.

Days after Blackburn's disappearance, FBI Agent Robert Graham arrives to investigate the peculiar events surrounding Alamogordo. Alongside him are Dr. Harold Medford and his daughter Pat, specialists in myrmecology, who are brought in to examine possible ant-related phenomena.

Dr. Medford introduces the catatonic girl to formic acid fumes, which shock her into consciousness. In a terrified outburst, she exclaims, 'Them! Them!' hinting at a larger threat, setting off alarms about what might be lurking in the desert.

While revisiting the original site, Pat Medford accidentally discovers a gigantic ant roaming in the desert. Following Medford's instructions, Peterson and Graham unleashing a barrage of gunfire at its antennae, culminating in the creature’s death.

Dr. Medford theorizes that the giant ants have mutated due to radiation exposure from the first atomic bomb test in Alamogordo. This revelation links the monstrous creatures to broader implications of mankind's experiments with atomic energy.

A helicopter search is initiated to locate the ants' nest. The team hopes to neutralize the threat, and upon discovering the nest, they deploy cyanide gas bombs in an effort to eradicate the growing insect menace.

Inside the nest, Pat finds evidence indicating that two queens have hatched and escaped. This revelation signals a daunting challenge as the authorities realize they are dealing with potentially widespread colonies of these mutant ants.

Authorities launch an international search to track down the mutant queens. Their investigation leads them to a freighter from Acapulco, where the crew is shockingly found dead, prompting the Navy to swiftly intervene to eliminate any threats.

As the search continues, Graham and Pat travel to Brownsville, Texas, where they meet a disturbed pilot previously institutionalized for alleging alien encounters with giant ants. They begin to connect disparate events throughout their investigation.

In Los Angeles, they meet a hospitalized man who recounts terrifying encounters with oversized ants in the drainage system near his room. The situation escalates as two boys are reported missing, raising the urgency to solve the mystery.

Desperate to find the missing boys, Peterson joins Graham and the Medfords to explore the drainage system. They discover the children but are ambushed by a giant ant, leading to a tragic confrontation that leaves the boys in peril.

Graham arrives with military forces, and together they prepare for a showdown against the remaining ants and their queen. The Medfords call for the use of flamethrowers to eradicate the ant threat, resulting in an intense duel against these monstrous insects.

After the intense battle concludes, Dr. Medford reflects on the consequences of atomic testing, drawing connections between the devastation caused by the ants and the broader ramifications humanity faces as a result of such experiments.