How are rainbows made?

S and I were talking the other day and he asked me if I knew how rainbows were made.  It's those random conversations, between my boys and I that I cherish and remember.  The little bits, about their days, that they tell me over bedtime snuggles.  The random thoughts and questions that come up while driving in the car.  Tonight, I asked him to tell me how rainbows were made.  The ending is 100% S.  The kid is no joke and he keeps us on our toes daily.  Enjoy.