Continuity: Mr. Furlong pushes Zeke into the fishing tank and it breaks, soaking him from head to toe with water. Moments later they are walking out and he is dry.

Continuity: In the scene where Casey is walking up to the school after his father drove him there, we see that Casey's bagstrap is backwards. Then they cut to the car, and when they cut back to Casey and all of a sudden, his bagstrap is turned the right way. The next cut is when coach Willis and Casey's father look at Casey and then Casey starts to walk up to the school again and his bagstrap is turned backwards again.

Continuity: In the scene where Zeke is in his car driving and fighting off Miss Burke, just before he crashes into the bus, you see him inside the car struggling to buckle his seat belt and therefore with all hands on it. Problem is, the camera filming the car from the outside clearly shows that the driver has both hands firmly gripped on the steering wheel and is swerving out of control.

Continuity: In one scene when Zeke is examining the alien thing under the microscope, he's wearing glasses. He puts them on the back on his head, in the next scene they are back on his nose again, and then suddenly they're back again.

Continuity: There's a swimming pool scene, where Stan tells the coach that he doesn't want to play the game. In the start, there's a shot where a kid jumps in the pool, the camera changes and the kid jumps in the pool again.

Continuity: When Casey is in the closet in the faculty room, the woman teacher, who is talking to the coach, gets water from the water jug and splashes it on her face. The camera cuts to her so you can see her face, but her hair is perfect and there isn't any water anywhere.

Other: When Zeke hands Mary-Beth the drug, when she takes the drug from him the lid is not on yet in the next shot the lid is on.

Audio problem: When you first see Stokely she says 'crash and burn, Casey' but if you look carefully you notice that her lips don't move with what she is saying.

Continuity: In the end when the giant alien squirts little aliens into Casey's face, the ones on his right cheek are seen going in twice.

Continuity: When Stokeley and Casey are chased into the swimming pool area, the alien pulls Stokeley to the floor. You can see a trail of blood from her mouth, then in the next shot the blood has changed into a small neat circle.

Other: After they kill the alien/teacher and leave the school they pass one girl in a blue/green tee-shirt with a waterbottle. Just one scene later you see this girl again under a tree, suddenly in front of them.

Continuity: In the scene they discover that Delilah is an alien, Casey gets Zeke's gun. Stockely takes the gun from him, and she's holding it one hand, but in the next shot it's in her other hand.

Continuity: When Elijah Wood is running with Delilah, he slips and falls, and when the camera changes, he's in a completely different position.

Continuity: When Stan is in the class and the teacher says something about read chapter four, Stan says they are in chapter five, and he puts his arms on the table, but in the next shot, his arms aren't on the table.

Continuity: In the scene where Marybeth tells Zeke that he couldn't be sure what he saw when they were all taking the drug-test to see who was an alien, we are shown a flashback of her using a weird extension on her alien finger to cut the blue end of the tube off and let the powder pour away. In the flashback, the blue end falls on the floor and is gone. Yet if you watch the first showing of this scene, when they were actually taking the drug test, we see a very clear shot of Marybeth just after taking the drug, and the blue end of the tube is intact.

Continuity: When Casey and Stokely are talking in the library, stokely's hair is constantly moving from behind her ear to in front between shots.

Other: In the scene where Zeke is examining the alien, he puts his glasses on to look down the microscope, but wears them at no other point in the film. Since microscopes can be focussed to the eyes of the user, most scientists take their glasses off to use a microscope.

Continuity: In the scene where Stokley is pulled into the swimming pool by the alien, you can clearly see that she is bleeding from her mouth. However at the end of the film, when she is in the cage thing, it looks like she has had a nose bleed.

Continuity: After Delilah refuses to take the drugs at Zeke's house and runs through the wall, Stokely's sweater keeps changing positions in and out of the house in different perspectives of the camera takes.

Continuity: Towards the end of the film, the students gather around the fish tank in the classroom. In the close-up scene the tank is brim full (the students actually touch the water when they lean on the tank). However, in the long shot, the tank is only half full.