How is that a honeybee reproduces parthenogenetically but also have males/drones?

Parthenogenesis is a process in which the unfertilised egg produces an offspring. In case of parthenogenesis in honey bees if queen dies (perfect female) who is the only fertile female in that particular hive, the worker bees (imperfect females) lay eggs by the process of parthenogenesis without mating. These develop into male drones.