Why is my brother so annoying? Umm… boys just will be boys. They will always try to look for trouble and attention. That is the keyword: Attention. The main reason why a brother would constantly pester you is just for attention. Maybe he is being bored and wants you to play with him. Maybe he finds getting you annoyed amusing. It’s just a way for him to get by his time, most likely since there is no other person he can play with other than you. The more you ignore him, the more he will try to grab your attention. It’s just all fun for him. Maybe if ignored long enough he will get bored and do something else.
Or you can do the other way and actually give in to his demands, show him compassion and willingness to have his fun. Children from the very young age learn that the parents is always the figure the authority, and be it fear or respect, they will only listen to them. This is partly because the parents actually pay attention to them, and they enjoy that. They learn quickly that getting someone attention is the fastest way to get someone to take care of their needs. When he can’t get yours, he will try over and over again, the only way he knew how, by annoying you to oblivion.