General Nuisance:
* As annoying as a fly buzzing around your head.
* Like a thorn in your side, constantly bothering you.
* As unwelcome as a guest who overstays their welcome.
* Like a persistent itch you can't scratch.
Loud Nuisance:
* As loud as a jackhammer in a library.
* Like a siren screaming in your ear.
* As jarring as a nail on a chalkboard.
Persistent Nuisance:
* As relentless as a dripping faucet.
* Like a broken record playing the same song over and over.
* As persistent as a mosquito at a picnic.
Unwanted Nuisance:
* As unwelcome as a spider in your bathtub.
* Like a bad penny, always turning up when you least expect it.
* As unpleasant as a bad smell you can't get rid of.
Remember to choose the simile that best fits the specific context of your writing.