Goofs

When the kids run and hide from the ant after he takes over their cookie, Amy had no cream filling on her mouth. In the next shot when she is telling Ron to be quiet, there is cream on her bottom lip.

From the window's side of Russell and Mae's bedroom, their bed is on the left side of their room, but when they are talking about little Russell, the bed is on the right side. Everything in the entire bedroom has switched sides from the first scene when Russell opens up his window to yell at Wayne.

The door to the attic is shown swinging wide open, and then immediately after, Nick is showing slowly opening that same door just wide enough for him to slip through.

When Tommy presses a button on the remote control after taking the tarp off of the lawn mower, the flag moves into the up position for a split second and then goes down. However, after he starts the lawn mower by pressing another button, the flag is in the up position again.

When Wayne runs to turn off the faucet on the side of the house, a pair of blue jeans is hanging on his left shoulder. In the next shot, the blue jeans are gone.

Szalinkski says that the Shrink Ray works by reducing the empty space in matter. If this is true, then the children's mass and weight would be exactly the same despite the reduced size. The trash bag Scalinkski would weigh several hundred pounds, the ant would not have been able to hold them, and the ground would have been compressing under the children's feet: the small surface area of their feet would mean that they would be exerting many tens of thousands of pounds of force per square inch.

During the scorpion/ant fight the scorpion is seen using his stinger multiple times not even striking the ant but the ground. Scorpions never waste their venom in random situations or even on prey that is smaller than themselves.

When Nick falls in the pollen, he is not worried about his allergies to it and says he's too little to breathe it in. But given his size and how covered he is in it, he very likely would have had a very strong allergic reaction, not a very small allergic reaction.

The title "Honey, I Shrunk the Kids" is grammatically incorrect. The simple past form would be: Honey, I Shrank the Kids. The present perfect form would be: Honey, I Have Shrunk the Kids. The literal version of the title is, consequently, incorrect.

Szalinski says the shrink ray works by removing the space between molecules; however, a solid object has very little space between its molecules making it impossible to shrink as much as they are shrunk.

At the beginning of the movie, a letter carrier is delivering mail. There is a mailbox with the flag up. He should open it, remove the outgoing mail, put the flag down and deliver incoming mail. However, he just opens the box and delivers the incoming mail, leaving the flag up. While this is true, it is not uncommon for people to forget to raise or lower the flag accordingly.

It is established in the film that Russ is not capable of whistling, but when Wayne and Diane Szalinski lean over the grass towards the end of the movie and all of the kids scream, Russ whistles loudly. Russ learned how to whistle.

In the film, the scorpion's size was shown equal to the size of an ant. This is impossible if compared to real life. The scorpion is not the same size as the ant. It is larger, although not large enough compared to the ant.

When Amy walks over to Ron to offer him a truce, her hands are clean, but then she puts mud in his hand when they shake. She was intentionally holding her hand in a way that hid the mud.

Wayne realizes at the end of the movie that the laser generating heat is what made his machine fail to work the way he wanted it to. But at the beginning of the movie he uses a cold fluid (presumably liquid nitrogen) to try to maintain the heat inside the machine. So he should have known about this already. While this seems like an contradiction, it seems he has accounted for cooling the machinery itself, but not the heat that the laser is applying to the target.

When the kids are going down the dust-pan, a screw top breaks on the way down, showing it's made of foam.

When Nick is in the Cheerios cereal and sees the spoon coming at him, the spoon moves in slow motion and frame by frame, while his dad behind moves at normal speed.

The kids, when compared to the size of the Lego block, should be larger than the ant.

Cables visible when Nick is sucked out of the earthworm tunnel.

In the second shot of the film where a mailman is seen walking and delivering mail for the Thompsons and the Szalinskis, a building can clearly be seen in the background which is painted in blue to stand in for the sky.

When Amy is on the phone, she says that she would meet her friends at the mall around 5 p.m. Just before she is shrunk, the clock that is on the wall reads 11:20. Later on, while shrunk, she says that she has six hours to get to the mall. Since there is no evidence of time passage, that would mean that she would be at the mall at 4 p.m., which is one hour earlier than what she told her friends.

When the ant shows up, and the kids are debating what to do, Russ jumps out from behind the grass and says "I say, that ant is ours", but his mouth isn't moving.

When the bell is first seen vibrating in Wayne's attic, the bell is ringing a series of short bells. When the bell is seen next, the bell is still ringing a series of short bells, but the ringing hammer is vibrating continuously.

When the kids are riding the ant, two members of the crew can be seen walking in front of them.

In both Nick and his father's glasses, reflections of set lighting and cameras can be seen throughout the film.

When Nick and Russ are on the bee, when the bee flies back down and hits the blades of grass, before Nick and Russ fly off a harness can be clearly seen on Nick for a few frames.

When Diane walks out of the mall to the pay phone, a sign says "Beverly Hills Mall", but it is in fact Plaza Inn, a mall in Mexico City.

Scorpions are usually desert creatures and would be a rare sight in an average family's backyard, especially if the immediate environment is a forest.

After the kids are shrunk and Szalinski destroys his machine, he thoroughly sweeps the floor of the attic, ridding it of both the broken microchips and the kids. In spite of this, his shrunken thinking couch and chair are still on the attic floor undisturbed an hour or so later.

When the kids encounter the stream of dog urine, Russ suggests that if they could get some rope they could make a log bridge, only to realise they don't have any logs either; later however, after the scorpion attack, they conveniently have both to erect a fence to keep out any further intruders.

It is stated that Antie is a baby. All ants that look like ants are adults. Actual baby ants look like maggots.

When getting out of the trash bag, Nick says they are a quarter of an inch tall. That would mean they are bigger than the ant.

Wayne states that Einstein invented the atomic bomb. Einstein didn't directly work on nuclear weapons, and they have no single inventor.

If the kids were 3/4 of an inch tall, the backyard would not seem like as much of a jungle (even if the grass was a bit high), the details in the attic floor would not be prominent, and Nick would have been noticed in Wayne's cereal.