Rats in my walls circulated as a standalone meme sound rather than a clip tied to a confirmed film or show, and its exact recording origin remains unclear. The phrase works because it sounds like the start of a serious complaint and then keeps going until it becomes a joke about paranoia and sleep deprivation. Shared on soundboards and in short edits, it is now used whenever someone is overthinking a noise, a neighbour, or a problem nobody else can see or hear.