text: The names Dexter and Dee Dee were both found in name books; "Dexter" caught Tartakovsky's attention for sounding scientific, while "Dee Dee" appealed to him because of its uniqueness and because he felt that it complemented that character's two pigtails. Before settling on these options, Tartakovsky had considered titling the series Dartmouth and Daisy. Explaining why he discarded this idea, Tartakovsky said that "Dartmouth doesn't exactly roll off the tongue" and that the name Daisy was already heavily associated with Disney. The title Dexter's Laboratory was not settled on until around midway through production of the series' pilot episode, "Changes".
  The ages of Dexter and Dee Dee are meant to be nebulous. Although Tartakovsky suggested that Dexter is intended to be about six to eight years old and that Dee Dee is "a couple years older", he stressed that he would "never want" to specify Dexter's exact age. Tartakovsky wrote Dexter as a hardworking, unspoiled "Midwest kid" who loves food and explained, "I'm not saying he's from Chicago, but there's a reason he's got his own burrito palace, just like I had growing up in Chicago."
  The sibling dynamic in Dexter's Laboratory was partially modeled on Tartakovsky's relationship with his older brother, Alex. Comparing himself to Dee Dee and Alex, who became a computer engineer, to Dexter, Tartakovsky acknowledged that he was most likely a "pest" to his older brother while they were growing up. Another time, he reminisced that as kids, he and his brother could each be a "pain in the ass" to the other. To illustrate one of the parallels between his childhood and the series, Tartakovsky noted that Alex had kept him from playing with "intricate" toy soldiers in those days, much like Dexter attempts to keep Dee Dee away from his inventions.