Patzer

At the end of the film, Ray comments on Carol's shorter haircut. In her last scene, her hair is back to its original length.

After the explosion, the bandage around Ray's head moves up and down.

When Ray and Carol talk in their parked Jeep, the headrests are missing. They appear as they pull out of the driveway.

During and after the scene with the bees, Walter walks towards his door three times.

When Art cuts the power lines, Mark is wearing a green beret. In the next scene on the roof, his beret is black. A few moments later, it's green again.

The antiquated "night vision scope" Mr. Rumsfield does not turn everything red when looking through it. That part of the scope is a red-lens flashlight. Infrared images appear black and white; black for cold, white for warm or hot.

The bird Art tries to shoot vocalizes like a crow, but is actually a raven.

When Dr. Klopek is ascending from the basement and they focus on his shadow on the opposite wall, the shadow behaves against the laws of physics. Since he is walking away from the light source behind him, his shadow should be getting smaller. A shadow only gets larger if you are walking towards the light source, with the shadow on the wall behind you.

This was done for dramatic effect to make his arrival more ominous and was an artistic decision that took a feat of moving light source behind him to achieve.

Walter rides home in a car with Illinois plates. One scene shows mountains in the background. Before the end credits, the camera zooms out on a map placing them near Des Moines, Iowa.

They are not Illinois plates, they are generic license plates that say "Drive Safely" along the top and do not identify a specific state, even though they may resemble the Illinois plates of the time period. The film is supposed to take place in a generic "Any Town, USA".

When Dr. Klopek is discovered as the murderer of the former neighbors, the Knapps, the trunk of his car pops open. Just before Ricky Butler points out the skulls and bones under the blanket, something under the blanket moves.

The skulls and bones are piled on top of each other haphazardly, obviously some of them shifted due to the movement of the trunk being popped open.

Carol goes away with Dave about halfway through the movie so that Ray, Mark, and Art can carry on with their plan to find Walter at the Klopeks' house. Later, after the house explodes from the gas main that Ray broke, Carol returns without their son who left with her hours earlier. Presumably, he stayed behind with the relatives that were mentioned as going to visit.

When Art telling story about Skip and the soda fountain you can see his breath when speaking but environment around him doesn't indicate it's cold.

The fact that it's night-time indicates that it's cold. His breath wasn't added in post, it would have been the actor's actual breath as he was talking so despite what you may think, it was obviously cold enough at night in Los Angeles for his breath to show, nevermind some town in the Midwest where the film it supposed to take place.

When Art and Ray are in the basement talking about the incubus and succubus, Art accidentally hits the lamp, causing it to swing back and forth. As the light slows down, a crew member hits the lamp again to keep it swinging.

At the beginning, when the paper boy is riding down their street, the camera gives a view straight down the street. The sign says "Mayfield Pl.", but it is positioned to show the cross street, not the street they live on.

After Ray walks out of the burning Klopeks' house, wires around the base of the porch supports can be seen pulling them back so that the roof collapses at that exact moment.

When Art goes up to the power line at the top of the pole, he is to the left of the shed in the Klopeks' yard. When he cuts the line, he falls backward, so he would have landed in Ray's yard, but mysteriously lands on top of the Klopeks' tool shed.

When Art jumps over the hedge into the Klopeks' yard, you can see that he jumps onto something that propels him over the hedge.

When the family sits down to breakfast, Art tracks some crow in his backyard with a Daisy pump action BB/pellet gun. He fires several shots that sound like a rifle.

There's a reflection (boom?) in the pool of water at end of Ray's driveway.

Art told Ray that he slipped a note underneath the Klopeks' door and Ray said he had also slipped a note underneath Walter's door when in fact he actually slipped it into the mail slot, not under the door.