|Season 1, Episode 11|
|Airdate:||February 21, 2003|
|Writer(s):|| Mr. Warburton|
|Storyboards by:||Matt Peters|
| Previous Mission|
| Next Mission|
Pesky Instrument Advances New Operative
- KND Operatives: Sector V
- Allies: Hamsters
- Villains: none
- Cameos: none
- Locations: Sector V's Treehouse, Unnamed stretch of interstate highway
- 2x4 Technology: S.K.Y.C.L.A.W.
Summary: Sector V try to destroy some pianos in a truck. During their first attempt, Numbuh 4 gets injured, and is replaced with a hamster. During the second attempt, they fail to destroy the last piano in the truck, the piano ends up falling on the rest of Sector V, leaving all of them injured and replaced by hamsters.
- This episode shows that the Kids Next Door refer to pianos as "Type-P torture devices." However, there are a few appearances in the series where they have pianos converted into control panels.
- While he struggles to leave the mission control room, Numbuh 4 grumbles "kiwi, marsupial, koala, wallaby," which is a reference to his Australian origin. However kiwis are actually from New Zealand whereas the other two are from Australia.
- This is the first appearance of the Hamsters Next Door. The next appearance is in Operation: H.A.M.S.T.E.R.. However, their appearance changes in the latter to look like Sector V.
- The reversed 4 on Hampster Numbuh 4's sign is a recurring symbol in the series. It's especially prominent in Operation: B.R.E.A.K.U.P. on Wally's vaseball uniform.
- This episode parodies how most children dislike being subjected to piano lessons due to the repetition and sheer boring nature.
- This episode reveals that Numbuh 5 is good at playing piano as she plays the opening notes to Chopin's Funeral March.