Flies don't go for light moths do. Might be left over warmth from the bulb or looking for a place to mate

So, I've been wondering for some time now; I usually have lots of flies in my room, since my window is always open, and they seem to fly around my light on the ceiling, even if I haven't turned on the light for a couple of hours. How come? Can anyone explain it to me? I know it's kind o f a stupid question, but I just want to know. xd