Yamada has just collected a lot of insects and is asked:
I'm guessing this is a set phrase along the lines of "What were you thinking?". I can't get any sense out of a literal translation.
I keep seeing this pairing of どう and する in things I can't translate literally e.g. どうしたの "what's the matter?". Is there some kind of rule I can apply that will help me understand these phrases?