how do i deal with these players?

When you play aram, and yes i know it's aram haha hehe hoho. Anyway, i got a rammus player who constantly thinks he can 1v5 because he is in a bush. As soon as the whole 5 man enemy team comes he goes in and dies. How do i deal with this when inside i wanna say "are you a fucking idiot? what makes you think you can 1v5"? It makes me feel like, why even bother trying in aram when people are gonna just do that? I know, its a fun game mode to have fun. But is it really fun if you got someone going in yolo and dying the entire game? Is it really fun?