Killer bees from South America have been breeding with the gentler bees of more northern climes, slowly extending their territory northward decade after decade. Entomologist Brad Crane (Michael Caine) has discovered that something is making them come together in huge, killer swarms. He wants to keep the General Slater (Richard Widmark) from using military tactics from further upsetting the balance of nature as they join to try to stop the swarms from approaching Houston.

Goofs for 
The Swarm 
 
Revealing mistakes: In the background, a paralyzed scientist in a wheelchair kicks a door open.

Continuity: Helena says they saw dead bee-covered soldiers outside, but no dead soldiers were in evidence earlier when the recon team enter the missile base.

Continuity: The morgue at the base only shows about a dozen bagged corpses, although over twice that number were visible earlier in the movie.

Continuity: Distance between Paul and the bees during the gasoline scene varies wildly depending on the POV of Paul or the bees.

Continuity: As Helena and Crane stroll during the train evacuation, scene changes from early evening to broad daylight.

Continuity: During the ambulance crash, the scene changes briefly from nighttime to broad daylight.

Revealing mistakes: When the stuntman crashes through the window of the base in Houston to fall to his 30-story death, hanging plants can be seen on the outside, revealing he is simply crashing from one room to another.

Factual Errors: The helmets of the NBC protective suits worn by the team that first visit the missile base are not connected to the rest of the suit.

Factual Errors: Bees die when stinging someone, but dead bees are almost never found at the site of any deaths.

Factual Errors: Slater, the county engineer, threatens to cut off water to the base. Military bases have their own water supply and are not dependent on the local municipality.

Factual Errors: Slater, a two-star general, is helping evacuate the citizens onto the train.

Factual Errors: The bees develop an immunity to the pesticide, although if it were as fatal as described, this would be scientifically impossible.

Plot holes: When the recon team enters the missile base, the dead bodies are unmarked and there are no trace of dead bees. Anyone stung to death by hundreds of bees would have highly noticeable hives, and bees die after they sting someone.

Plot holes: Crane, a civilian, is wandering the military base despite the fact that it was under lockdown, and the recon team had to use key codes to enter.

Plot holes: The military sends jets to track the swarm. Jets travel at hundreds of miles an hour, while the bees are identified as moving at 5-7 mph.

Plot holes: Crane shows a slide of a shot of a wing taken from the only dead bee they were able to find, although thousands of bees would have died during the attack on the missile base.

Plot holes: Slater sets up roadblocks to stop the bees.

Plot holes: The military manages to evacuate the entire city of Houston in less than a day.

Plot holes: The military plans to destroy the bees by setting the entire city of Houston aflame, overlooking the fact that bees can fly.

Plot holes: The military sets Houston on fire by sending out small squads of men with flamethrowers, rather than an aerial bombardment.

Audio/visual unsynchronised: Crane calls on Maureen as if she had raised her hand, although the character never does so.

Anachronisms: The recon team use revolvers, although the standard military sidearm since the 1930's has been the Colt .45 Automatic or the Baretta 9mm.

Crew or equipment visible: As the flamethrower team sets a car on fire, you can briefly glimpse a film crew rushing up with water to put it out.