questions - "Does he go bowling?" or "Doesn't he go bowling?"

Let's say we know a boy called Jonny and he goes bowling twice a week. My daughter has asked me which of the following questions are correct.

1. Does Jonny go bowling?


2. Doesn't Jonny go bowling?

We are wondering, why is it that the answer to both questions is "yes", although the second question starts with a negative word?