An indoor-outdoor novelty device which simulates the flight and illumination patterns of real fireflies in dark conditions. The device provides the illusion of a flying illuminated firefly, appearing and disappearing at pseudorandom positions. This behavior provides a realistic firefly effect especially when multiple devices are present. This effect is due to the unique configuration of this device under microcontroller control. The device may be configured as completely self-contained, self-operating and self-charging; not requiring user intervention for daily operation and can be located indoors or outdoors.