What's our purpose in this world?🌍

So this is so unrelated to any of this but, my brother that is almost 11 years old just asked me all this question that even left me wondering... He said, why are we here? Why don't just animals live here? Where do we all live? And what's our purpose here? I was speechless... And it just left me wondering too 💭 And to be honest I didn't know how go answer his questions.