How to Annoy Your Brother
To annoy your brother, go into his room and use his stuff when he's not around. Or, you can be really loud and obnoxious when he's busy doing something, like homework or talking on the phone. You can also try hiding his phone, keys, or computer and pretend you don't know where it is when he's frantically looking for it. If he's on his computer, try shutting off the internet so it stops working.
Mimic his voice. Any time your brother says anything, repeat what he said, but in a high-pitched girly voice. This has been driving little brothers crazy since the dawn of time. This is especially effective when he's telling you, "Stop doing that!" or "I'm telling!" When your parents come in, quickly switch over to your regular voice so you don't get caught. Take bites off his plate. While you're eating dinner, wait until nobody is looking and start sneaking bites off his plate. Make sure it's his favorite food, too. Before he notices, make comment like, "Jeez, where's all your food going." Boss him around like you're his parent. Little brothers want to be older so badly that the more you draw attention to their youth, the more annoyed they'll be. Treat him like he's much younger than you all the time. If you have to do chores together, keep commenting about how he's slow, or can't keep up with you because you're older. Assign him chores, even if it's not your job to do chore-assignments. Call him a baby any time he asks you for help, or doesn't understand something. Always talk about how he's too small, too short, or not old enough to know something. Make stuff up. Little brothers are impressionable little goofs. One way to annoy them is to make up ridiculous lies about the world and get them to believe it. If you can even get them to repeat it like it's real? That's a total win. Tell your brother avocados are actually dinosaur eggs. And they're poisonous. Tell your brother he wasn't actually born, your parents grew him in a bucket from catfish heads. Tell your brother that you have the power to read minds. He's thinking, "No you don't." Tell your brother that the dog speaks when he's not around. And says it wants to eat him. Tell your brother Star Wars is a documentary. It really happened. Tell your brother when he turns whatever age he turns next, his nipples will fall off, then grow back. Embarrass him in front of his friends. If your brother has some friends coming over, it's a great time to mess with him and embarrass him in front of others. Bring out some of his baby pictures, or talk about something embarrassing he did the day before when his friends are over. He'll get really annoyed. Nuclear warfare: Dump a glass of water on his bed, so it looks like he peed it the night before. Wait until his friends come over and let them find it. Be really careful about doing this. If you're a cool older kid, you should probably have better things to do than messing around with your younger brother in front of his friends. You might just look like a loser doing this. Use the silent treatment. If you really want payback for something, just ignoring your brother is sometimes the best option. He probably wants attention, and keeping that from him will drive him even more crazy than anything you can do. Don't let him do stuff that you're doing. If you're going to watch a movie, say he can't, because it's only for older kids. Freeze him out of whatever you're doing. Try to be his friend, too. Younger brothers usually look up to older kids. Just because your little brother might be annoying sometimes, Try to remember that you can be a good influence on him too. Instead of trying to annoy him, try to teach him to be cool. Don't make him a nuisance. Only use these methods to get back at your brother for doing something that's mean. Don't make this a regular habit. Go into his room. Older brothers are going to get pretty defensive about their rooms. If your brother has his own room, just keep going into it without being asked. Ask him a million questions and start messing with his stuff. Wait until he starts getting up to tell your parents, then leave really quickly and go back to your room. If they ask you about it, say, "He's making it up." Do something weird in his room while he's out, like pull out all his clothes and put them in a pile, or take sticky notes and label everything. Put one on the window that says, "Window." Put one on the computer that says, "Computer." Find his change jar and label it "143 cents." He'll be so confused. Play innocent. If he tries to beat you up, or chases you out, tell your parents you just tried to ask him a question and he started hitting you. Make annoying noises. Wait until your brother is busy doing something, like playing a complicated game, talking to a girl, or doing his homework. Then, it's time to strike. Make stupid noises with your mouth, or with your armpit, or with your toys. Make a big racket. Make sure your parents are in another room, so you can stop in enough time before you get into trouble. Hide his stuff. Hide his phone, keys, books for homework, or anything specific that he thinks is really important. Make it really hard to find, putting it in a box in the attic, or somewhere strange out in the garage. Be careful not to leave incriminating evidence in your room, if you are to do this. Be smart, don't hide stuff under your pillow. If its found, you can always play ignorant and no one will be able to prove it was you. You can also come clean when your brother is looking. Say, "Oh, you need your phone? I know where it is. Give me a ride to the comic book store and I'll tell you." Shut off the Internet when he's on it. Find the Internet router in your house, if you have one, and find the "reset" button. When your brother's busy talking to chicks on the Internet, keep hitting the reset so he'll get really annoyed. If you don't know where the router is, ask your parents to show you, because you're curious. Don't let on that you want to mess with it. Just say, "How does the Internet work? Can you show me?" They'll be impressed. Try to snoop on him. Older brothers and privacy are made to be separated. If your brother really values his privacy on his computer, phone, and in his room, start trying to invade it as much as possible. Mess with him in little ways that'll drive him nuts. Try to swipe his phone. Delete contacts on his phone, or change the names of people. Find his best friend and change it to "Stupid McButtsniffer." Try to log into his Facebook and make embarrassing posts, or change his pictures, or comment on other people's stuff with dumb comments. Wake him up really early. If your brother went out really late the night before, wake him up by blasting some loud rock music, like Linkin Park or AC/DC, or starting a battle scene from Lord of the Rings really loud. Do it in his room at 6.00 AM on a Saturday. Instant annoyance. If he has an alarm, reset it for like two hours earlier than he would normally wake up. Nobody should have to wake up at 4 am. Except your older brother. Ease off sometimes. It might not always seem like it, but you're lucky to have a brother, and you'll probably get along a lot better when you're older. Annoying your brother, however annoying he may be to you, can be pretty immature and get you both into trouble. Try to get a long as much as you can. Instead of annoying an older brother, try to learn as much as you can from him. Older siblings usually know a lot more about their younger siblings. Instead of annoying him, try to understand why he does what he does. 
Mimic his voice. Take bites off his plate. Boss him around like you're his parent. Make stuff up. Embarrass him in front of his friends. Use the silent treatment. Try to be his friend, too. Go into his room. Make annoying noises. Hide his stuff. Shut off the Internet when he's on it. Try to snoop on him. Wake him up really early. Ease off sometimes. 