Soldier ants, or marabunta, live peacefully for 40 to 50 years in gigantic ant civilizations in remote jungle colonies. There they breed until an internal clock is triggered and they erupt, swarming over the country in the billions and eating everything in their path including vegetation, wildlife, and humans.

When dozens of species of native birds and ground animals were observed in the Amazon rain forest in panicked flight from some terrifying phenomenon deep in the jungle, MacGyver and his friend Dr. Charles Alden formed a small expedition to investigate. They encountered Lucien Trumbo, who owned a cocoa plantation in an isolated region of the jungle and who acted as their guide. In the jungle, they discovered an army of soldier ants leaving a path of total devastation two miles wide and ten miles long. As Dr. Alden attempted to photograph the ant army, they swarmed over him, killing him before MacGyver could reach him.

All of Trumbo's workers fled in fear except Luiz, who remained behind with MacGyver and Trumbo to face the invading army. The ants breached flooded irrigation ditches and killed Luiz as he attempted to maintain the water level. MacGyver constructed a flame thrower to burn them out, but they also survived the perimeter of fire. Finally, MacGyver's homemade nitromannite explosive successfully destroyed the irrigation dam which flooded the fields and drowned the ants.

Cross Reference: Charles Alden, Brazil, Luiz, Lucien Trumbo

Episode Reference: Trumbo's World