In a Brazilian village, a father and son break into the beekeeping and research facility of Dr. Franklin Miller to steal honey, but the bees attack and kill the boy. Sometime later, Miller and his employee realize that someone broke into the killer Africanized bee cage. The next morning, Miller complains to his wife Sandra that he could have paid for extra security if he received his promised government funding. After reviewing his accounts, Miller believes someone has skimmed nearly $500,000 from South American agricultural project funds. Meanwhile, an angry mob accuses Miller of bringing “devil bees” to the village. Miller explains the bees were already in the country, and he was trying to domesticate them for honey production. When the father carries his dead son through the crowd, blaming the “devil bees” for the boy’s death, a riot ensues, destroying the hives and unleashing thousands of deadly bees. Miller hides Sandra in a safe room before he is stung to death. One month later, in New York City, Dr. John Norman and Dr. Sigmund Hummel meet with a United Nations (U.N.) agricultural committee. Norman hopes the U.N. will provide funds to help them develop a less dangerous form of the Africanized bee, but the council refuses their request. Days later, Sandra arrives in New York City with a case of smuggled Africanized bees and meets with Norman and her “Uncle Siggy” Hummel. The next day, the trio meets with a group of businessmen interested in Africanized bees. As honey producers and cosmetic manufacturers, they believe the bees could be very profitable. Hummel warns that the bees are currently too dangerous, but if the companies invest in their research, they can find a way to domesticate the bees in a few years. However, the businessmen say they will find other ways to import the bees if Hummel and Norman do not cooperate. After the meeting, Hummel fears the businessmen have already acquired the Africanized bees and resolves to eradicate the pending infestation. Over the next few months, numerous people are attacked by swarms of killer bees across the country. As Sandra and Norman conduct research, Norman discusses his work with microwave radiation and suggests they use it to destroy the killer bees, but he notes that his results thus far have been strange and unpredictable. Norman fears the government will blanket the country with insecticide and pollute the environment. Sandra believes the synthetic pheromone they recently created has potential and Norman proposes they test it in natural conditions. The next day, Sandra and Norman, dressed in protective gear, locate a wild beehive. Norman notices a radar station in the distance and worries that the intense radiation emitted from the dishes can alter the killer bees’ genetics. When Sandra and Norman spray the pheromone on the hive, the male drones become confused and attack each other. Later, the businessmen meet with Sam Brennan, Undersecretary of the Department of Agriculture. Brennan is furious that the businessmen have failed to control the bees that he helped smuggle into the country. Brennan decides to exterminate the bees and meets with Norman to discuss his research. Norman explains how his synthetic pheromone causes the male drones to attempt to mate with each other instead of the queen bee. If the government will pay for manufacturing the pheromone in large quantities, they can spray the infected areas without harming the environment. Brennan agrees. Back at the laboratory, Sandra asks Hummel to go over her deceased husband’s accounting books, hoping to confirm Miller’s theory that someone stole their funding. When Norman returns, Hummel asks about Norman’s research with microwave radiation. Norman says the radiation altered the genetic structure of the bees and produced bizarre behavior, but he does not understand what it means. Hummel reports that bees communicate with sound and movement then shows Norman his research, which indicates a bee language pattern. Hummel says he is working on a translation. Sometime later, Norman coordinates with the military and the United Nations to deploy his pheromone solution. It works perfectly. Back at the laboratory, Hummel completes his review of Miller’s accounts and tells Sandra that the thief is someone in the Department of Agriculture. Hummel meets with Brennan in Washington, D.C., and informs him of the stolen funds. Brennan promises an investigation, but after Hummel leaves, Brennan orders the murder of Hummel, Norman and Sandra. When two assassins break in to the laboratory and shoot Hummel, bullets break a window and unleash a swarm of killer bees, killing the hit men. Norman and Sandra return to find an injured Hummel. Before he dies, Hummel tells them that the bees have evolved and are immune to the pheromone. The insects now have intelligence and reasoning capabilities. Hummel empathizes with the bees and begs Norman and Sandra to continue his work, translating the insects’ language. The next day, the bees kill Brennan and the new breed of killer bees terrorizes the nation. The military unsuccessfully attempts to control the insects with bombs and fire. One night, the bees swarm the laboratory but do not harm Norman and Sandra. The couple talks out loud to the swarm and promise to decipher their language. Months later, Sandra and Norman address the United Nations, explaining that radiation has caused a genetic mutation in the bees, provoking an evolutionary leap. Sandra and Norman have translated the bees’ language and pass on the insects’ message: humans must stop destroying the environment. As the United Nations dismiss Norman and Sandra’s theory, bees swarm the conference room. Norman and Sandra tell the council that the bees will not harm them if they accept the bees’ terms and that there is no other way the human race can survive.