The Lab Brat

“The Lab Brat” was the seventh episode of the first season of Daria.

Summary
At Lawndale High School during science class, Janet Barch presents a lesson on acquired behavior involving a lab rat, interspersed with comments regarding her hatred of men and descriptions of how her husband left her. Ms. Barch's dislike of males extends to her male students but she praises Daria’s imaginative answer to a question. She concludes the lesson by assigning teams of students for a home science project consisting of training a rat to run through a maze. Daria is paired with Kevin and Brittany is paired with Upchuck.

That evening at the Morgendorffers Helen speaks with Daria about her upcoming project. Helen commentsthat associating with Kevin could help Daria socially and ignores Daria’s comments on Helen's lack of sincerity. Kevin arrives shortly afterward and Daria distracts him from the project by turning on the Pigskin Channel...while she retires to the garage to work on the project alone.

Meanwhile, Brittany has arrived at Upchuck’s house under a heavy disguise. She warns him not to get ideas about her presence, but Charles blackmails Brittany( with a photograph of her and Oakwood High's quarterback in a compromising position) into doing his personal chores.

At the Morgendorffers Kevin continues to watch football in the TV, oblivious of Quinn's flirting and strong hints that Kevin should go out with her. Quinn seems intent on her efforts to seduce Kevin, even refusing Brittany's entrance to the Morgendorffers. Kevin eventually goes to the garage (breaking part of the maze Daria had already built) where he and Daria are surprised by Brittany, who quickly deduces Kevin hasn't been working and therefore must have been seduced by both Morgendorffer sisters.

The next day, as Daria and Jane are discussing recent events at Pizza King, they are interrupted by Kevin (intending on arranging another visit to work/watch TV), Brittany (who tells Daria to stop seducing Kevin) and the Three Js (who are in awe of Kevin and try to pick Daria up).

Brittany, meanwhile, kidnaps the mouse used by Daria, leaving it in her brother Brian's (lack of) care. She intends to exchange it for Kevin (who she now believes is dating both Morgendorffer sisters). The next day at school, Daria is able to trick Brittany into exchanging the mouse for Kevin. Unfortunately, its treatment by Brian has left it traumatized and worthless for the project.

The students present their various projects: Upchuck has built an elaborate maze and trained the mouse, but Barch's refusal to let him speak and Brittany's ignorance of the project (as she had been too busy slaving for Upchuck and spying on Kevin) cause both to fail. As for Daria, she makes an insightful presentation on the mouse's fear as negative reinforcement, playing on the teacher's neuroses, and earns a top grade - while Kevin, who had been mute and striking poses during Daria's speech, barely receives a passing grade (which he still considers cause for celebration).

“The Lab Brat” and Fanfic
The Lane cats Zachary and Taylor get into the act in "The Maze Thing" by Richard Lobinske.

Janet Barch's rants and extreme misandry, which constitute the basis for the character and would be developed in later episodes, have become synonymous with this character in fanfiction.

Quinn's long and involved descriptions of (to the rest of the family) mundane experiences in her life causes Helen to practically plead for Daria to talk to her. Quinn's mindless chattering characterizes many dinner scenes in Daria fanfic.