You can legally annoy library patrons without getting thrown out! The secret is in one word: subtlety. If you have a penchant for annoying people, follow this sure-fire way to grate someone's nerves. The best part is this: they can't throw you out!
All of these annoying things rely mainly on planning. You can't let anyone know that you are intending to annoy. You have to act as natural as possible. If you're an actor or have acting experience, it will come in handy.
These are all intended to distract one person or just a few people at a time. These are not enough to disrupt the entire library. You really have to be a die-hard annoyer because the only person in on these "pranks" is you.
Assume breathing problems.
When someone is nestled into a good book or trying to write a research paper, heavy breathing can really distract them. Go to the reference section where people are studying and sit near someone. Read your book for a few minutes and then start. Take a deep, slow breath in your nose and exhale slowly out your nose. Wait a moment and do it again. Switch it up by taking a deep sigh. Sniffle a few times. Then mix it up and start all over.
Chew gum with your mouth open.
Need I say more?
Swish papers.
There is no one more important than the person who thinks he is so important with all his papers. Be that person. Take a folder with all kinds of papers and spread them out on a table in a study area. Shuffle them around. Straighten them up by collecting them all and tapping them on the table. Read a paragraph or two from a book or just pretend like you're reading, then all of a sudden, frantically search for something. Scatter your papers, flip through them and make as much noise with the paper as possible. Then suddenly stop. Once the quiet is sustained, grab a paper and wad it into a ball as quickly as possible. In a dead silence, this sound can be as loud as a shotgun and can make people jump. (I know because I have tried it. It's hilarious.)
Have a tickle in your throat that you just can't get rid of.
Clearing your throat can easily distract and annoy. Start out with short deep grunts while keeping your mouth closed. As the other patrons start to fidget from you, take it to the next level and fake cough a couple of times. This takes some at-home practice because you don't really want to hurt yourself. You can hurt your vocal cords if you strain too much. The other patrons are also scared of this tactic because they will think you are sick and contagious!
Read to yourself, only in a loud whisper.
Take what you're reading very seriously, especially if you're reading the tax forms. Dramatize it as if you are reading Shakespeare, but keep it in a whisper.
Mimic another patron.
Follow nearby and use your peripheral vision to watch someone else. As they reach for a book, you reach for a book. If they squat down to the lower shelf, do the same. If they walk to the end of the aisle and go around the shelf, go down the opposite end onto the next aisle. Don't ever look at them directly. Follow them the entire time they are in the library.
Take another patron's books.
Not the books out of someone's hand, but the books they return to the shelf. If they pull a book off the shelf, look at it, and then put it back, this is a perfect opportunity for you to snatch it at a supersonic speed. Declare "YES!" in a loud whisper and walk off. Come back a few minutes later and repeat this same action every time they put a book back on the shelf.
The emergency phone call.
Take your phone out and whisper loudly "I'm in the library." Allow a fake conversation to take place where something terrible is happening to someone you know. Say phrases like: "What?" "You're kidding me?" "Oh my God!" "Are you going to the emergency room?" "Your entire leg?" "Are you serious?" "Sorry man, I can't help you right now. I'm reading." Whisper all of this, but it's sure to grab the attention of some people and is sure to disturb others. A few minutes later, act like your phone is ringing on vibrate, look at and answer in an aggravated tone "What is it man?" Then continue the conversation as if someone needs your help and you're refusing because you're reading.
Make noises with writing instruments.
Click your pen or tap your pencil on the table. Start lightly at first then build up to a consistent non-stop beat. Then start humming with the beat. Hum a song that most people know such as "This is the song that never ends." They will have it in their heads all day.
Go to the audio section.
Pick up an audio cassette book and then go to a book aisle. Tap the audio cassette case on your leg. Act like you're browsing for a book. Tap some more. Follow patrons and tap your leg harder.
As you practice and use these annoying tactics in your local library, you'll find which ones work better than others. You'll also gain a sense of what kinds of people are easier to annoy than others. You'll be able to tell when people are getting really annoyed. Have fun!