Teens Next Door (or TND) is a secret organization for the best and loyal KND operatives who were selected to stay with KND after they have turned 13. They pretend to be decommissioned or traitors so they don't blow their cover to the other KND operatives that don't know the TND exist. They are known to be "special agents" for KND, but they must pretend to join the Teens to spy on them from the inside.
- Maurice (Numbuh 9)
- Chad Dickson (Numbuh 274)
- Unknown female from the credits of the episode Operation: M.A.U.R.I.C.E.
- Sector V or at least numbuh 1 & 5
- Numbuh 362
- Numbuh 60
KND Operatives that know about the TND
- Numbuh 5 -- Found out from Maurice in Operation: M.A.U.R.I.C.E.
- Numbuhs 1, 2, 3 and 4 -- They found out in Operation: T.R.E.A.T.Y. from Numbuh 5 and Chad.
- Supreme Leader (Numbuh 362) (possibly) -- As the head of the KND itself, he or she would likely know about it.
- Decommissioning Squad (possibly) -- Just like the Supreme Leader, the Decommissioning Squad (including the head of the squad (Numbuh 86 in this case)) would likely have to know about it in order to help chosen teens fake and/or falsely escape their decommissionings.
- False decommissioning is not the only way to hide the TND; operatives, like Chad Dickson, falsely betrayed the KND to become a Teen Ninja in order to infiltrate the Teens.
- On the Rainbow Monkey Website, it says Numbuhs 60 and 362 are fugitives. This could imply they were selected to become TND operatives because of their skill. Thus, they may have also eventually feigned their betrayal in a similar way Chad did.
- It's implied in the end credits of Operation: M.A.U.R.I.C.E. that there are also undercover adult operatives for the KND, which in turn would suggest that there's an "Adults Next Door" organization.
- It's possible there's a Negative counterpart of the TND, known as the Destructively Nefarious Teens (DNT), like the Destructively Nefarious Kids from Operation: P.O.O.L.
- Before the Junior High Rebellion of 1999, the decommissioning age was 16, and selected operatives migrated to the TND at age 16. However, because of the insurrection, the decommissioning age was lowered to 13.
- Furthermore, it's likely there were loyalist teenagers who still defended the KND from the teenage rebels. So, after the uprising, these loyalists were rewarded positions as TND operatives for their loyalty and faithfulness. However, this is just a theory.
- In contrast to what has been previously said, Numbuh 362 may have never known about the TND as she seemed generally upset at Numbuh 9's decommissioning ceremony. Thus, it's possible that neither the Supreme Leader nor the Decommissioning Squad know about the TND.
- However, given Numbuh 9's dialogue at the end of Operation: M.A.U.R.I.C.E., it's likely that they do, but it's not acknowledged for secrecy's sake.