Trivia: The name of Mark's frog is Beans. Steven Anthony Lawrence plays Dylan in this film, and his character's nickname on the Disney channel show "Even Stevens" is also Beans.
Trivia: Despite playing one of the principal roles as Hank, Ashton Kutcher is not credited in this film.
Trivia: In the 1950 version of Cheaper by the Dozen, the father, played by Clifton Webb, dies.
Trivia: In the original dozen family there was a girl named Mary Elizabeth Gilbreth. Mary along with some of her other siblings got diphtheria and she, at age 6, was the only one to die from it. The family never got over the loss of Mary and still referred to themselves as the dozen even though all 12 children were never contemporaries. This explains why very few references have Mary's passing in them including the Gilbreth books or even their papers.
Trivia: When the father is talking to Hilary Duff in her room about the mother not coming home for two weeks music can be heard playing in the background. Listen closely its a song by Hilary duff that she is listening to.
Trivia: The scene where the twins dump the whole bag of dog food was completely improvised.
Answer: It seems that the fact the family can't take care of themselves is added to part of the humour of the film. 12 children is a lot, and think about all those rows and all that mess.
Hamster ★
It's not like they couldn't take care of themselves. As shown with the breakfast scene at the beginning, they seem to function pretty well when they all get along. Tom and Kate were just usually home more frequently than some other parents. It also didn't help that it was the first time that one of the parents was gone for an extended period and the parent that was left home (Tom) had never had to deal with all the kids on his own. Also, the only time we see complete chaos in the house is the first day that Kate has been gone. After that the kids are more behaved (at home).