A screenplay was initially written by Richard Kelly, who greatly departed from the source material by writing a dark, violent adaptation of the story set in a post-apocalyptic world. The studio reportedly found the script far too disturbing for a children's movie, rejecting it in favor of the final script written by the novel's author, Louis Sachar.
Caveman finds a scorpion crawling on his bed. A trainer set the scorpion on the bed and stood just off camera. The trainer touched the scorpion lightly with the end of a straw and it lifted its tail up. Then the trainer blew some air through the straw and the scorpion began to crawl.
In the beginning of the film, there is a rattlesnake near the holes the boys are digging. One of the young men walks up to the snake, puts out his bare foot, and the snake bites him. A trainer put a bull snake, which is a non-venomous snake, down on the ground and put a box over it to contain it before filming began. The trainer removed the box and the actor walked over near the snake and put his foot out. The director yelled, "cut" and a trainer replaced the Bull snake with a real rattlesnake and doubled as the actor, putting his bare foot near the snake. Several trainers stood just off camera holding nets and snake hooks just in case the snake decided to wander. The snake was immediately retrieved by a trainer and removed from the set.
Nine "Bearded Dragon" lizards were on call for the parts of the lizards in the film. A non-toxic children's finger paint was used on the lizards to make them appear bright in color. Computers helped create some of the lizard action and production created fake life-like lizards for some of the other scenes.
The "yellow spotted lizards" mentioned in the movie do not exist. There are only two venomous lizards in North America: the Gila monster and the Mexican beaded lizard, which live in the American Southwest and northern Mexico.
Dulé Hill played Sam. He later acted as Shawn's (James Roday) co-star, Gus, on the TV show "Psych." In the episode "65 Million Years Off" when seeing all the holes that the paleontologist dug on the land, Shawn mentions "that this is like that movie with Sigourney Weaver." He also mentions Shia LaBeouf and Jon Voight. Gus keeps guessing movies but never correctly guesses the movie that he appeared in, Holes.
In 2006, three years after this film was released, author Louis Sachar published a sequel to Holes called Small Steps which focuses on (mainly) Armpit and (partially) X-Ray moving on with their lives about two or three years after leaving Camp Green Lake. The story involves a ticket scalping scheme, a disabled ten yr old girl named Ginny, a chance encounter with a famous pop star named Kaira DeLeon, and a murder plot. There are currently no plans to adapt the sequel to the screen.
In the novel, when Stanley and Hector are about to leave Camp Green Lake, Squid asks Stanley to call his mom for him and tell her that Alan (Squid's real name) said he was sorry. In the film, it is Armpit who asks Stanley to do this and uses his real name, Theodore.
In the film, Stanley is shown to live with both his parents and his grandfather; he and his grandfather even share a room together. But in the novel, Stanley is only ever mentioned to be living with his parents. There is never any indication in the novel that his grandfather is even still alive, much less that he lives in the same apartment. Also, the novel erroneously labels Stanley's father as Stanley Yelnats II, but in actuality he's Stanley Yelnats III.
Shia LaBeouf who plays Stanley Yelnats IV and Jon Voight who plays Mr. Sir in this film, would go on to work together again four years later in Transformers (2007). However they would not share as much screen time together or exchange much dialogue between their characters.
Shia LaBeouf and Max Kasch who play Stanley Yelnats IV and Zigzag would work together again two years later in The Greatest Game Ever Played, which like this film was distributed by Walt Disney Pictures.
During one scene, we see a young man carrying a baby pig. Then the pig is drinking from a stream and then the young man is pulling a full-grown pig by a rope. The pigs were not babies, but older pigs that were small. A very large pig acted as the full-grown pig being led by a rope at the end of this scene. The young actor was shown how to handle the pig ahead of time by the trainer. The stream was very shallow and was checked out ahead of time by the trainer to make sure it was safe for the pig and the young actor to walk in and drink from. Another grown pig appeared at the end of the scene to make it appear as if the piglet was now grown. A trainer attached a halter that fit around the pigs' front legs and neck. The young actor was given the end of the rope, which he held while delivering his dialogue. The actor then gently tugged on the rope to get the pig to walk with him. A trainer stood off camera holding a bucket of grain and calling to the pig to encourage it to walk in that direction. The sounds of the pig squealing and grunting were sound effects added in during post-production.
According to the cast commentary by the actors who play Stanley, Zero, Zigzag and Squid, the table that the D-Tent Boys sit at in the mess hall also served as the audition table for most of the boys who went out for their respective roles.
Towards the end of the film, all of the boys at Camp Greenlake run to greet Stanley and Zero after they've returned to the camp and X-Ray shares a few emotional words with Stanley just before he and Zero leave. However, in the novel, only the boys from D tent come to greet them, except for X-Ray. He lingers behind the others and then quickly returns to the Wreck Room.
At the end of the film it is revealed that Mr. Sir's real name is Marion Sevillo, and that he is a former criminal who has violated his parole by carrying a firearm. None of this was in the book, however as the film's screenplay was written by the author of the book it can be assumed that these details are canon.
The D Tent Boys' real names are as followed: 1. X-Ray = Rex Alvin Washburn (his full name is revealed in the sequel novel Small Steps). 2. Armpit = Theodore Thomas Johnson (his full name is revealed in the sequel novel Small Steps, which incidentally focuses on his life two or three years after Camp Green Lake). 3. Squid = Alan. 4. Zigzag = Ricky. 5. Magnet = Jose. 6. Zero = Hector Zeroni 7. Caveman = Stanley Yelnats IV 8. Twitch = Brian. 9. Barf Bag = Lewis.
In the novel, when Stanley finds the gold tube, ZigZag is the one who notices and asks him about it before Stanley gives it to X-Ray, while in the film, it is Magnet who notices and asks about the tube. Also, in the novel, Stanley decides not to point out the heart shape with the letters K.B. on it, while in the film he doesn't hesitate to point it out to X-Ray and the other boys.