The drawings of characters during the end credit roll were all done by the children of the animators. The same is true of the picture that Sid draws of himself on a cave wall. Sid's drawing was done by 3 year old Will Shefelman, son of a story artist Dan Shefelman. The story artist working on the scene was having difficulty drawing like a 3 year old so he consulted an expert.

John Leguizamo tried 30 different voices for Sid. After viewing a documentary about sloths, he learned that they store food in their mouths; this led to him wondering what he would sound like with food in his mouth. After attempting to speak as if he had food in his mouth, he decided that it was the perfect voice for Sid.

Despite the Dodo's less than brilliant survival instincts, they outlived all of the major character's species. Dodos were wiped out around the mid to late 17th century, whilst woolly mammoths (Manny) died out 10,000 years ago (a dwarf race existed until 1700 BC), ground sloths (Sid) are widely accepted to have become extinct some 2500 BC (although it has been proposed a small group survived till 1550 AD), and saber tooth tigers (Diego) were wiped out around 10,000 BC. Not even Neanderthals like Roshan and his father survived the Dodo.

The humans are not Homo-Sapiens, but Neanderthals. They never speak in the film.

All the actors were encouraged to improvise as much as possible to help keep the animation spontaneous.

This is the only film in the Ice Age series to show human characters, and the only Blue Sky Studios film to have any human characters for almost a decade. Blue Sky wouldn't feature any human characters again until the 2011 film Rio.

Though Scrat was designed as a fictional animal, in 2009, scientists in Argentina unearthed the remains of a small, extinct mammal resembling a shrew with long fangs. This animal was given the scientific name of "Cronopio Dentiacutus", in tribute to Scrat.

The film was originally intended as a drama but Fox would only accept it as a children's comedy.

When Sid, Diego, Manny and Roshan are in the ice tunnel, a Flying saucer appeared and Roshan makes a "Star Trek"-hand sign. (Vulcan Salute)

The first drawings seen in the cave (before entering the giant area with the mammoth drawings) are replicas of the earliest known cave drawings (found at Lascaux, in the south of France). They have been dated at somewhere between 15,000 and 17,000 years old.

Chris Wedge, director, is the voice of Scrat, but has no intelligible dialogue; the plan to have Scrat talk was quickly dropped, as he worked better as a silent character for comedic effect. The name 'Scrat' is a combination of the words 'squirrel' and 'rat', as Scrat has characteristics of both species; Wedge has also called him "saber-toothed squirrel." Scrat's opening adventure was inserted because, without it, the first real snow and ice sequence wouldn't take place until about 37 minutes into the film. This was the only role intended for Scrat, but he proved to be such a popular character with test audiences that he was given more scenes, and has appeared in other movies.

No cave paintings of the sabre-toothed cat Smilodon have ever been found.

Originally, Sid was supposed to be a con-sloth and a hustler, and there were even two finished scenes of the character conning some aardvark kids and a very suggestive scene with two female sloths later in the movie. Sid was also supposed to have a female sloth named Sylvia chasing after him, whom he despised and kept ditching. All the removed scenes can be seen on the "Super Cool Edition" DVD.

20th Century Fox initially expected the film to open around the $30 million mark. Its opening weekend was $46.3 million.

Many of the animals appearing in the sequels to the film were designed initially for the first Ice Age but were cut.

Writer Michael J. Wilson has stated on his blog that his daughter Flora came up with the idea for an animal that was a mixture of both squirrel and rat, naming it Scrat, and that the animal was obsessed with pursuing his acorn.

Was Blue Sky Studios's only film to be nominated for the Academy Award for Best Animated Feature until Ferdinand (2017), fifteen years later.

Supposedly the reason Don Bluth refused to make the film is when 20th Century Fox said they wanted it to be CG after the failure of 2D animation, Bluth refused due to his personal hate for fully CG animation and angrily walked away from the project.

All ground sloths in this film and its successors were designed with traits of both prehistoric ground sloths and modern tree sloths. Initially in design, Sid, as a ground sloth, resembled one of the more notable species of ground sloth, the Megatherium, which was the size of an elephant. The species of sloth that Sid and the others resemble most in the finished films is a species of Caribbean ground sloths that were more the size of pigs.

Some additional character names: the baby is Roshan, his mother is Nadia, his father is Runar. The sabers are Soto, Zeke, Oscar ("haughty saber") and Lenny ("fat saber"). The female sloths in the pool are Jennifer ("He's not much to look at...") and Rachel ("All the sensitive ones get eaten."). The "rhinos" are Carl (the one with thick horns) and Frank (the one with thin horns). The source for this information is from an autographed original script purchased at auction. There is a signed COA from 20th Century Fox Archives, auction item number ICE0032.

Each of the frozen beings Sid sees in the ice is connected to an installment in the franchise: a carnivorous fish, a dinosaur, a set of sloths, and a flying saucer.

In the movie, Manny is referred to as Manfred, Manny, that neeny weeny mammoth, Manny the Moody Mammoth, Manny the Melancholy, friend, Jumbo, the mammoth, Fat Hair Boy, and buddy.

Jack Black's first animated film.

James Earl Jones and Ving Rhames were originally considered to play Manny.

Hollywood's 8th full CGI animated feature.

The only stipulation that consulting anthropologists from the American Museum of Natural History in New York insisted on with the production was that there should be no dinosaurs. They would have been long gone 20,000 years ago, though a great deal of the animals shown in the film didn't live in the same eras or locations as the main characters. Dinosaurs were finally included in the second sequel, Ice Age: Dawn of the Dinosaurs (2009), the explanation being that they survived extinction in underground caves.

The "rhinos" in the movie are actually titanotheres (or brontotheres), mammals from the Oligocene period and are no relation to modern rhinos as they went extinct, several million years before the Ice Age depicted in the film. Ice Age rhinos looked more like modern rhinos, but covered with thick fur coats just like the mammoths.

The production team originally thought of turning the 20th Century Fox logo into ice when it appears before the film. Even though it can be seen in one of the trailers, they cut that out and placed the regular logo in the film, but pushed up a bit so you can see the bottom portion of it.

Blue Sky Studios' 1st feature film.

The filmmakers made it so that many of the scenes with Scrat appear directly after dramatic moments in the film.

Is the only film in the Ice Age franchise to be released on VHS in the US. ("Ice Age: The Meltdown" (2006) was also released on VHS in Italy)

Antonio Banderas was considered for the role of Diego.

The film opened in March 2002. Within three weeks it had become the first film of that year to pass the $100 million milestone in box office takings.

Chris Wedge regrets that he didn't get the bunny from his short Bunny (1998) into the film as an easter egg.

On the 2-Disc Special Edition DVD of the film, Ray Romano calls the movie a "dramedy" and explains why the movie is both drama and comedy, and this is corroborated by director Chris Wedge in his own interview on the special features. Fox wanted a children's comedy, so Blue Sky took that direction, but kept the drama aspect a notable element of the movie, hence why the cast and crew refer to it as a "dramedy."

Gone Nutty (2002) aka "Scrat's Missing Adventure" was created exclusively for the DVD release.

The responsibility for animating Sid's snowboard sequence was given to animators who went snowboarding in real life.

This feature is included in the first wave of Blu-Ray releases by Fox. A total of five movies were included in this, the others being Fantastic Four (2005), Behind Enemy Lines (2001), The League of Extraordinary Gentlemen (2003) and Kiss of the Dragon (2001).

The fat saber-tooth cat named Lenny was actually described as a scimitar cat in the film's Essential Guide book.

Chris Wedge claims that Scrat's species of saber-tooth squirrel has a scientific name given by the writers but Wedge has since forgotten it.

Pre-production took over a year before any animation occurred.

This was originally set to be directed by Don Bluth and Gary Goldman by Fox Animation Studios until the failure of Titan A.E. (2000) put paid to that. With the departure of Bluth and Goldman, the project migrated to Blue Sky instead.

The eighth-highest-grossing film of 2002.

Movie signage and the book version include a female sloth named Sylvia, who is not seen in the released movie. In the book, Sid manages to avoid accompanying her on the migration south, because she is interested in a commitment.

The fourth computer-animated film to be rated PG by the MPAA after Antz (1998), Dinosaur (2000) and Shrek (2001).

The first movie to be produced by Fox Animation since Titan A.E. (2000), which also featured John Leguizamo).

At 77% fresh, this is the only film in the Ice Age franchise to be certified fresh by Rotten tomatoes, let alone fresh at all, as all four of its sequels are rotten. It was also Blue Sky Studios's only certified fresh film until Horton Hears a Who! (2008) and The Peanuts Movie (2015).

Blue Sky Animation has been developing improvements in computer-generated characters for over 15 years now. It was responsible for some of the aliens in Alien: Resurrection (1997) and the talking cockroaches in Joe's Apartment (1996).

20th Century Fox launched it on the home market with a marketing budget of $85 million, the largest amount they had spent up till then on a DVD release.

Blue Sky has engineers on its staff who understand the physics of sound and light and how these elements will affect movement in characters.

This is the only Blue Sky Studios film to have the "Twentieth Century Fox presents" credit.

Denis Leary's second animated film. The first being A Bug's Life (1998).

This is 20th Century Fox's second animated film composed by David Newman. The first was Anastasia (1997) which was released five years before this film.

Kristen Johnston voiced Sylvia in three deleted scenes.

Some of the screams in the film were reused a few times.

Leonardo DiCaprio was considered for the role of Sid.

After the folding of Fox Animation Studios, this project was offered to Disney who turned it down. Ironically, with the Disney acquisition of 20th Century Fox in 2019 (which includes Blue Sky), the property now belongs to the House of Mouse.

This made $383 million from a $59 million budget.

The character Sid was originally intended to be a con-artist and a hustler. For example there is a finished scene called paying toll with the aardvarks this scene shows Sid conning three young aardvarks this scene was cut from the final version of the film because the team felt that the audience would've disliked him so he was revised to clumsy sloth instead also there is an alternate version of the mud bath scene which was more suggestive than the version in the final version this scene where Sid says some suggestive stuff and gets kicked in the groin this version was removed because it was inappropriate for children,received negative reception and would've gotten the film a PG-13 rating.

The first theatrically released animated film for Alan Tudyk. Later he'd go onto voice Cholly the Chalicotherium in this film's sequel Ice Age: The Meltdown (2006), Milton the Sloth in another sequel Ice Age: Continental Drift (2012), Mr Squeegee the Robot in Astro Boy (2009), King Candy in Wreck-It Ralph (2012), Duke of Weselton in Frozen (2013), Alistair Krei in Big Hero 6 (2014), Duke Weaselton the Weasel in Zootopia (2016), Heihei the Chicken in Moana (2016), and KnowsMore in Ralph Breaks the Internet (2018).

Robert De Niro was considered for the role of Manfred.

Three years in production.

Leonardo DiCaprio, Johnny Knoxville, Dave Foley, Adam Sandler, Michael J. Fox, Ewan McGregor, Jerry Seinfeld, Billy Crystal, Eric Idle & Danny DeVito were all considered for the role of Sid before John Leguizamo was cast.

The only Ice Age film not to feature Ellie, Crash and Eddie.

Cedric the Entertainer's first animated film and only one outside DreamWorks' Madagascar franchise and Pixar's Planes duology.

Jane Krakowski's first animated film and only one outside Sony Animation's Open Season franchise.

The only Blue Sky Studios film to have a logo with a blue dash this doesn't include Robots (2005) released 3 years later which had an updated logo for the release although the old logo with the blue dash does appear on the poster of Robots.

This is the only film in the Ice Age franchise to be scored by David Newman.

Both Jack Black (The role of Zeke) and Cedric the Entertainer (The role of Carl) starred in this film and starred later in a DreamWorks movie Jack Black starred in Shark Tale (2004) and the Kung Fu Panda franchise (2008-2016) while Cedric the Entertainer starred in the Madagascar franchise (2005-2012) in Shark Tale (2004) Jack Black voices a great white shark named Lenny in the Kung Fu Panda franchise (2008-2016) he voices a giant panda named Po also in the Madagascar franchise (2005-2012) Jack Black voices an aye aye named Maurice what's more Shark Tale (2004) , Madagascar (2005), Kung Fu Panda (2008), Madagascar: Escape 2 Africa (2008), Kung Fu Panda 2 (2011), Madagascar 3: Europe's Most Wanted (2012) and Kung Fu Panda 3 (2016) were all composed by Hans Zimmer and jointly with John Powell (who composed Ice Age: The Meltdown (2006), Ice Age: Dawn of the Dinosaurs (2009) and Ice Age: Continental Drift (2012) ) in case of Kung Fu Panda (2008) and Kung Fu Panda 2 (2011) and not David Newman like this film.

Stephen Root's first animated film.

Most of the cast had made this film their first voice over role in an animated film for all voices of the main characters except for John Leguizamo, Denis Leary and Diedrich Bader: John Leguizamo was in Don Bluth's animated film Titan A.E. (2000), another animated film by 20th Century Fox, Denis Leary was in A Bug's Life (1998) and Diedrich Bader was in Bartok the Magnificent (1999), also by 20th Century Fox and Recess: School's Out (2001).

The only film in the Ice Age franchise to receive an Academy Award nomination for Best Animated Feature.

Albert Brooks was considered for the voice of Manny.

Brad Garrett was considered for the role of Carl.

Chris Miller was considered for the role of Oscar.

Cody Cameron was considered for the role of Lenny.

Diedrich Bader's third animated film after Bartok the Magnificent (1999) also developed by 20th Century Fox) and Recess: School's Out (2001).

Denis Leary (Diego), Cedric the Entertainer (Carl), and Stephen Root (Frank) have also appeared in films by Pixar Leary previously appeared in A Bug's Life (1998), as Francis the Ladybug, Cedric later appeared in Planes (2013) and its sequel Planes: Fire & Rescue (2014), as Leadbottom, and Root later appeared in Finding Nemo (2003), and its sequel Finding Dory (2016), as Bubbles the Yellow Tang.

James Earl Jones, Ving Rhames, Johnny Depp, Pierce Brosnan, Kevin Kline, Robert De Niro, Albert Brooks, Nicolas Cage, Sylvester Stallone, Kevin Costner, Keith David, Bruce Willis, Jeff Bridges, Jim Belushi, Michael Keaton & Val Kilmer were all considered for the role of Manfred before Ray Romano was cast.

Anthony Hopkins, Ralph Fiennes, Kiefer Sutherland, Toby Stephens, Kevin Spacey, Liam Neeson, Tommy Lee Jones, Clint Eastwood, Gene Hackman, Tim Curry, Ian McKellen & Lance Henriksen were all considered for the role of Diego before Denis Leary was cast.

Christopher Walken, Alan Rickman, Sam Elliot, James Gandolfini, Patrick Stewart & Michael Wincott were all considered for the role of Soto before Goran Visnjic was cast.

This is the first Blue Sky Studios film to use Hanna-Barbera, Warner Bros. and Cartoon Trax Volume 1 sound effects.

According to an interview with Jay Leno on July 12th 2012, Denis Leary's character Diego originally died near the end of the film, which caused the test audience of children to burst into tears, so it was re-done.

When Sid tells Manny how his family abandoned him, he asks Manny about his family. Manny doesn't answer, and then tells Sid the following morning he should be loyal (in Sid's case, grateful) to a mate if and when he gets one. We find out what happened to his family in the cave drawings scene. Manny had a wife and child who were killed by humans, and he's still grieving for them, so he knows full well about being loyal to a mate. This is likely a reason why he denies his feelings for Ellie in the second film at first too.