What is the old snack called whistles?

Excuse me, could you please clarify what you mean by the phrase "the old snack called whistles"? Are you referring to a specific type of snack food that was popular in the past and known by that name? If so, could you provide some additional context or details about the snack, such as its ingredients, taste, or where it might have originated from? Alternatively, is there a specific cultural or regional reference that I may be missing? I'm eager to learn more about this intriguing snack, so please feel free to elaborate.