Continuity mistake: The burnout of Houston takes place at nighttime, but when the bees attack an ambulance driver who then crashes into a building, the scene changes briefly to broad daylight.
Continuity mistake: When a larger group of soldiers enter the compound at the beginning of the film, the door of the compound opens to let them inside in one shot, but in the next shot the door is closed and opens a second time.
Continuity mistake: When Mrs Durant is swatting the bees off the table at the picnic site, you can see Mr Durant is holding a white plastic cup in his left hand. However, in a close-up of the table, you can see that the cup Mr Durant is holding has gone.
Revealing mistake: When we see the bees flying off the trash cans and on their way to Marysville, you can see it is simply reversed footage.
Continuity mistake: When the Marysville residents begin panicking in the carriage during the train evacuation scene, you can see that Olivia De Havilland isn't wearing her reading glasses, but in the next shot she has glasses on and takes them off again.
Continuity mistake: When Paul's mother is using a napkin to swat the bees off the table at the picnic site, she knocks over a white plastic cup, but when we see a full view of the table in the next shot, the cup has disappeared.
Visible crew/equipment: During the Houston burnout scene, the flamethrower team set a car on fire. You can briefly see a film crew member rushing up with water to put it out.
Factual error: When Rita is in the doctor's surgery for her prenatal visit, the chest X-ray in the background is upside down.
Revealing mistake: If you look carefully when Paul's father is killed by the bees at the picnic site, you can see he is breathing as his belly is expanding.
Revealing mistake: When the bees attack the train during the evacuation scene, a guard falls backwards and his arm hits a lever. You can see that the 'bees' in this scene are just colored pellets.
Continuity mistake: Near end Caine and one other leave Widmark. Caine says he will get Marcia Nicholson. When in her room he wraps her in a blanket covering her "ghost style" over her head and part of her face. Outside the room the blanket has fallen to her shoulders (maybe could happen) but next cut the blanket is again over her head.
Revealing mistake: When Felix puts down his cup of coffee whilst speaking to Mr Harris in the cafe, you can see his cup is empty.