There is no one answer to this question as different fruit fly species have different preferences. However, some possible reasons why fruit flies might be attracted to mirrors include: 1. The reflective surface of the mirror could be mistaken for water. Fruit flies are attracted to water and use it for laying their eggs. 2. The mirror could reflect other fruit flies, which the fruit fly mistake for conspecifics (members of the same species). This could trigger the fruit fly's mating instincts. 3. The mirror could be providing the fruit fly with a new and stimulating environment to explore. Fruit flies are known to be attracted to novel objects in their environment.