Why does my brother steal all the time?
It may be because he is jealous of what you have - either that, or he's trying to annoy you or wants you play with him (if he's younger). If you show a lot of reaction, he'll continue to do so.
what is he stealing
He is iron man! Kidding, we need more information mate.
He's a bad boy
he might want something ,but he doesn't have money for it he might need some discipline
I really can't answer cause there are no details
may want some one to notice him
Probably just being rebellious
some people have urges to steal, most never act upon them, but some do. it can be a way to get a thrill in life, he could be jealous, maybe he wants to sell it for money, there are any number of reasons.
he is a thief
He's probably a Kleptomaniac ...it's actually a real mental disorder!