Continuity mistake: When they all are trying to lure the graboids away from Val, Rhonda looks down the pipe running down the from the water tank. A piece of cloth soaked in water is tied around the pipe and water is dripping from it. When it cuts to Rhonda climbing down the water has stopped dripping.
Continuity mistake: When the snakeoid is chasing Val and Earl after they lose their horses, they run along a fence and the monster causes all the fence posts to fall over backwards. But shortly after, all the fence posts are seen to be upright, although some are tilted a little to the right.
Factual error: Throughout the entire film Burt holds all of his rifles' butts underneath his armpit, rather than against his shoulder. A trained "survivalist" such as him would surely know better. Holding the "elephant gun" in such a way would most likely break his arm, wrist and hand when it fired.
Revealing mistake: When Valentine grabs Mindy off the pogo stick, you can tell it's been stuck into the ground so the actress can stand on it and be ready for Kevin Bacon to grab her (as opposed to Kevin Bacon grabbing her while she's bouncing). After she's grabbed, you can see the pogo stick shake back and forth without falling over.
Audio problem: Right after Bert kills the second graboid he gets on the radio and says "we killed that mother-humper". Val replies "...be advised there are two more mother-humpers". However Val's lips don't seem to be saying "humper". This occurs even in unedited versions of the film.
Continuity mistake: When Val and Earl are relaxing with a couple of cold ones after they bury the trash, Val's recliner chair changes. From the side it is a brownish-rust color cloth material. In the next shot, from the front view, it is greenish leather. This scene takes place after Rhonda's near miss with the graboid but before the first guy, old Edgar, is found dead.
Revealing mistake: When the graboid starts pulling Jim underground, his wife hands him a board to keep him above ground. You can see the thick board bend rather easily while his wife hands it to him. Also when Jim is sucked under ground it bends quite easily as well, as if it were styrofoam.
Continuity mistake: Reba gets out of their truck at the compound and looks through the binoculars - in the foreground you see the tractor and trailer they use to escape are very close together, or are attached already. When Kevin Bacon and the other guy figure out to use it, the camera pans around and the tractor and trailer are 60-100 feet apart.
Add timeJoseph Greene
Continuity mistake: When Val is getting the fuse lit on his bomb to throw to the last Graboid, we see his hands separated, one holding the bomb and one holding the rope. The camera angle changes to a close up of his hands, where they are now both holding both the bomb and rope.
Continuity mistake: The green fuzzy dice in the guys' truck change over and over. Sometimes they're stuck up behind the rear view mirror, sometimes they're hanging down. Granted, they could fall and the guys could stick them back up again, but in one scene when they're behind the mirror, the faces of the dice that are visible from the front change.
Continuity mistake: After Burt reports on the radio that he has killed the graboid in his basement, there are shots of the towns people celebrating. The sky behind all of them is different, specifically the mother and her daughter. In other shots there is blue sky. In these shots there are darker clouds.