Goofs

The patrol car used by Troopers Peterson and Blackburn has an emergency water bag hanging in front of the hood from the ornament. This is visible in every scene up through the time when the car arrives back at the location of the trailer with Drs. Medford. When the car is seen from the front after the party disembarks, the water bag is no longer visible.

Gramps Johnson can be seen breathing when the cops find him, although he is already supposed to be dead at that point.

The photograph of the queen egg case examined by Dr. Harold Medford shows the egg case in a different position than it was when it was photographed by Dr. Pat Medford.

During the final battle in the sewer, one of the ants is the one that had its antennae destroyed in the desert, as the antennae are still broken.

The pattern of the patrol car's front seat cover (plaid), first seen when the little girl is placed in the car, is different from what is seen when the same patrol car arrives at the site of the trailer (striped).

Sergeant Peterson and Bob Graham are seen throwing cyanide gas bombs into the ant nest without wearing gas masks, only wearing gear to protect against the heat. Cyanide gas is so deadly to humans that this simply would not have happened that way.

After the discovery of the first giant ant, Dr. Harold Medford says, "We may be witnesses to a Biblical prophecy come true - 'And there shall be destruction and darkness come upon creation, and the beasts shall reign over the earth.'" However, this quote is not found in the Bible.

Hydrogen cyanide gas, used to kill the ants in the New Mexico nest, has a molecular weight similar to air, such that it would not sink to the ground as seen inside the nest. It is also extremely flammable, and the use of a flamethrower inside the nest as seen would have incinerated everything and everyone.

While the Army is searching the storm drains of Los Angeles for the new nest of giant ants, they are seen to be using radios for communication. Radios do not work underground - especially in reinforced concrete tunnels.

When firing the white phosphorous at the ant hill, they load and fire a 3.5 rocket launcher. When viewed from the rear, a blast is seen coming from the back of the launcher. The launcher is basically a hollow tube. When the rocket is fired, the tube is empty. However, just after the back blast, which launches the rocket, the dummy rocket can still be seen in the tube.

Dr. Harold Medford identifies the ants as Camponotus vicinus, a species that does not sting its victims. However, one must remember that these ants are mutants.

(at around 5 mins) Sgt. Peterson is fingering various items strewn across the trailer's floor, including some paper money...except the bills are clearly phony and don't resemble the U.S. dollar at all. The reason for this is that it is against the law to use real money on-screen. Prior to the 1970s, production companies would actually design and print their own currency that was completely unique to differentiate it from real bills and from the other companies' fake currency.

The little girl, briskly walking a straight line, is found only 3 miles from where she had escaped the trailer but she had escaped 10-12 hours earlier, giving her an average speed of only 0.25-0.3 mph. However, it is possible that she occasionally meandered in circles for long periods.

When Sergeant Peterson and Patrolman Blackburn are investigating the car and trailer and walk behind the car, there is no trailer hitch on the car to pull the trailer.

During the first encounter in the desert, both Ben Peterson and FBI guy Graham are using 6-shot .38 cal revolvers; however, 20 pistol shots can be heard without reloading.

Early on, while the cops investigate inside Gramp Johnson's Store, there is a lamp in the right-hand corner of the screen that is swinging due to strong desert winds. The string that is causing the swinging can be seen.

The characters are showing speaking in normal voices inside of a 1950s-era helicopter. Even in helicopters today, the sound levels approach 130 dB, which means that hearing protection must be worn. They couldn't hear one another if they were in such a craft, and they would have been in pain from the experience.

(at around 5 mins) Sgt. Peterson is seen sifting through flotsam on the floor including paper money. Several minutes later, at the Johnson Store, Peterson is examining paper money in a cash register. It is obvious the paper money is fake.

Ants have six legs, but only one print is found in the sand near the trailer by the officers, and in the desert by Dr. Harold Medford.

Studio lights are visibly reflected in the goggles the actors are wearing during the sandstorm.

After the S.S. Viking is overrun by giant ants, it is then reportedly sunk by a cruiser named the USS Milwaukee. There was no ship by that name in the US Navy in 1954. The most recent USS Milwaukee at that time was an Omaha-class light cruiser which was scrapped in 1949.

During the final battle, the mechanical controls are visible on the attacking ant on the right. (This mistake can only be seen on VHS and laser disc - it is blacked out on the DVD reissue.)

When Pat and Robert spot the desert nest from the helicopter, several cars and what appear to be two buses or trucks can be seen parked on a dirt road behind the nest supposedly hidden in this isolated location, "in these hundreds of thousands of square miles of desert".

Not long after the FBI agent sits down to talk with the Captain the shadow of crew equipment can be seen on the right wall next to the door.

In the store scene, as the overhead lamps swing back-and-forth due to the 'wind', a cord (likely fishing line) can be seen tugging on one to make it move.

When they are examining the second "footprint" discovered, someone on the production crew accidentally jostles the camera, as the screen briefly jumps up and to the left.

The first aerial shot of the ant nest, which is supposedly in the middle of empty desert, reveals not only a well-maintained road but at least 3 clean parked cars within a hundred feet of the as-yet undiscovered nest.

In the supposed New Mexico desert are some beautiful specimens of Joshua trees, which grow in California, Arizona, Utah and Nevada, but not New Mexico.

When Peterson suggests they go to Gramps Johnson's store, it is full daylight, but when they arrive, it is full dark, even though the distance is only twelve miles.

When Dr Harold Medford (Edmund Gwenn) asks Bob Graham (James Arness) where the 1945 A-Bomb was detonated, Graham points to a spot on the map a little south of White Sands, NM. Trinity Site, where the bomb was detonated, was over 70 miles north, as the crow flies, from White Sands.

When Peterson is investigating the storm drains in LA, he reports that he has detected the same "brood odor" he smelled in the nest in New Mexico. But when he was in that nest, he was wearing a gas mask to protect him from the cyanide gas they had used to kill the ants. He hardly could have detected a "brood odor".

While the three leads are in the New Mexico nest, all are covered head to foot for protection, yet none of them wear gloves, not even Peterson, who shoots a flamethrower. Dr. Medford touches the ant saliva with her bare hand, prompting Peterson's famous quote about "spit".

When Bob Graham asks the drunk in hospital how long he had been seeing the giant ants, it is implied that the "long time" mentioned may have been as long as 5 months. However, during General O'Brien's broadcast on martial law, it is stated that the giant ants were first discovered "a couple of months ago". Given the timing involved from that point forward, for a queen ant to make it all the way to Los Angeles, begin a nest, raise offspring to giant size, and the fact that the male ants had been dead for only 4-5 weeks, it must be that the "long time" was only a few weeks.

Shadow of microphone can momentarily be seen on the wall of the room where Dr. Harold Medford asks to see the little girl.

Although the other personnel in Army uniforms at the mineshaft are wearing helmets correctly, with both helmet-liner and "steel pot" outer shell, Robert Graham (James Arness) wears only the lightweight helmet-liner, without the steel pot. Although understandable for the actor, since the liner alone is much more comfortable than adding the heavy steel pot, the liner alone provides little head protection - much less than a typical "hard hat". Its main function is to support the steel pot, which is what provides the actual protection for the head.

When the Doctor and his daughter arrive, all of the characters are standing next to the engine exhaust on the B-25J. This would have very uncomfortable as the plane had just landed and the engine would still be quite warm.

When Peterson finds a bloody shirt inside the trailer, he says that the "blood must be 10, 12 hours old". Yet the "blood" is soft, not hard and crusty as dried blood would be.

When the FBI agent points out on the map where the first atomic bomb was tested, he indicates Southwest of Alamogordo near where White Sands Missile range is located. The Trinity Test Site is actually about 100 miles north of that region, far to the Northwest of Alamogordo.

Bob Graham says they can fly from Washington D.C. to Brownsvill, TX in three hours. That's almost 1200 miles, so the Kibees' plane would have to travel about 400 mph, beyond the capacity of a plane he would have access to.