Curiosity / House Pest.Curiosity: After being pranked too many times by Alvin, Simon vows revenge against him. Alvin dismisses it at first, but the Chipettes convince him that, being the smart one, Simon is very effective at playing pranks. Alvin attempts to smooth things over with Simon, who does forgive his brother, but still vows revenge. When a mysterious box is delivered for Simon, and he instructs Alvin not to open it while he is away for a couple of days, Alvin fears the contents of the package are Simon's revenge against him, and goes to greath lengths to see what the contents are. Finally, Alvin smashes the package with a baseball bat, then learns that the contents of the package were actually his birthday present from Simon, and that the scare that Simon initiated by telling him not to open the package while he was gone was the revenge on Alvin that he had promised.
House Pest: Ms. Croner's house becomes infested with termites, and she asks the Sevilles if she and her cats can stay with them until her house is fumigated. Dave reluctantly agrees, and the Chipmunks soon find their new house guest to be more of a pest, as she ends up making demands of them, such as Simon to do her laundry, Theodore to make her tea, and weaseling Alvin out of his TV time. The boys attempt to drive her out of the house but, growing up with a bunch of brothers herself, Ms. Croner is always one step ahead of them. After these attempts fail, the Chipmunks discover that Ms. Croner and Russel the Exterminator appear to have feelings for one another, so Alvin tries to play matchmaker, hoping that it will bump her to the top of his work list.