Other mistake: Whenever Verne is inside his shell, he has a tail (and references to it "tingling" are made throughout the movie), however, when he is out of his shell he has human-style buttocks and no tail.
Continuity mistake: When Verne gets hit by the bike and hockey stick and goes through the hedge, there's no tire track on his shell while flipping through it until he shows R.J. the bike track. (00:15:25 - 00:18:00)
Plot hole: It would have taken much longer to build the 54 acres of homes than the animals hibernated, so there's no way they couldn't have known what was going on around them.
Continuity mistake: During the huge raid on Gladys' house, the animals use Tiger's collar to activate the pet door and get in. Later, Stella goes through the pet door, which opens despite the fact that she doesn't have the collar.
Continuity mistake: The first time Vern goes through the hedge, he enters into the backyard of a house, but when he returns via the hockey stick, the hedge borders the street, not the back yard. (00:13:50 - 00:15:30)
Continuity mistake: When the Depelter Turbo is used to capture Gladys, Dwayne and Vincent, the beam of light that goes straight up shows us that is is coming from a city (Chicago, perhaps?)just south of the tip of Lake Michigan. However, when RJ opens the bag of tortillas, the orange mushroom cloud shows his location as being farther to the west and south.
Continuity mistake: When Verne pulls the cord for the See and Say, it moos, but there is no cow picture on the wheel. Although it looks like the wheel started on quiz, It would have to choose a sound from the pictures on the wheel. (00:55:50)
Continuity mistake: When R.J. pulls the wagon to stop Verne, The ground hook and chain is next to the right front wheel. But while R.J. and Verne are talking there's no chain or hook to be seen until they start pulling the wagon from each other. (00:40:25 - 00:40:55)
Continuity mistake: When RJ opens the nacho cheese-flavored chips, Verne is standing to the right of Lou and Penny. When the camera switches to being inside the bag, Verne is standing to the left of Lou and Penny. (00:18:15)
Continuity mistake: When Vern is pulling the wagon to return the food the two squeaky toys that Vern inadvertently gets stuck on his feet are near the back wheels of the wagon. But they were not there in the previous shot as R.J. walks toward Vern to tell him to be very quiet.
Continuity mistake: When RJ is getting chased by Vincent, the right window of the Verminator's truck gets smashed. However when the truck is flying in mid air (into Gladys' house), the right window is intact.
Plot hole: When the animals awake from hibernating, the trees are full of leaves, as if it was summer instead of spring; plus, flowers wouldn't pop out of the snow fully germinated, especially since the snow would be all melted by the time the tree leaves fully grew.
Continuity mistake: As RJ rifles through his backpack looking for the whipped cream to make Hammy appear rabid, he tosses several items out and/or over his shoulder, most notably a toilet plunger. The items are gone when Vern confronts RJ in the same spot moments later.
Suggested correction: Based on the time he could've put them back during the attack.
Continuity mistake: In the scene where Gladys (the president of the Homeowners' Association), the exterminator man, and the bear are being hurt by the contraband contraptions designed to exterminate the animals, a bright light develops, and the animals watching have to put sunglasses on. When the light disappears, Verne and RJ have tan lines everywhere except where their glasses were. But in the next shot of the animals (they're celebrating), Verne and RJ's tan lines have disappeared.
Factual error: In the beginning when the animals are waking up from hibernation, it shows Ozzie and Heather running out of the log, which shows they hibernated, but opossums don't hibernate.
Continuity mistake: After the rocket wagon scene, RJ lands on the ground and the red wagon and the blue cooler land next to him. In the next couple of shots, the wagon and cooler are further away from RJ.
Continuity mistake: When Verne lands on one of the girls with the cookies, you can see his reflection in her eyes. You can see his shell around his neck (it looks like a popped shirt collar), however, he already came out of his shell at this point.
Revealing mistake: When Stella the skunk yells at the cat, she pokes him on the face. However, you will notice that the hand looks a lot like a human hand, not Stella's.
Other mistake: When Lou climbs the tree, to tear off some bark to eat, the bark should stay on his belly but it is on his back when the kids are complaining.
Suggested correction: He rolls backwards and his back grabs the bark off the tree.