Why do some kids try to ruin the focus of the classroom?

They don't like learning, fine don't... but why do some kids disrupt the whole class? I was in class, the teacher is explaining a topic and then there's this one kid behind me that just starts shouting random words. The teacher isn't even focusing on him, he's not tryna get attention or something. He's literally just shouting random words. And they're not even coming out of a joke. They're just random. Do they have a problem? I'm talking about this one kid I have encountered in my life but there are many kids who do stuff like this.<br><br>Edit: I use he/him pronouns because the person I described was a boy, but I'm sure there are plenty of girls who do this