Perhaps there is a grain of truth in the Hollywood stereotype; many of us writers are natural 'night hawks', keen of mind, active, thoughtful; falling asleep is the most difficult thing in the world when there is a plot brewing in one's mind. Just try sleeping while events are playing themselves out, when the ideas you've had during the day have taken off under their own steam. Before you know it the world is reacting to your characters and suddenly your mind is a microcosm, alive, vivid, like another universe next door to our own. In this pocket universe great events happen and they must be written down – then suddenly your train of thought is interrupted and your partner can be heard calling to you. “Get to your bed, you have work, in 4 hours. Move!” Here goes another missed opportunity because real life can never let you go for long.

But why is it, the night time seems like a natural time to write? No doubt there are many reasons for it. The darkness wipes away all around it leaving a canvas for the writer's imagination. The silence allows the writer to imagine soundscapes unhindered by the sound of TV sets blaring out garbage, birds chirping away, traffic and other such noises that color the daytime soundscape. Such noises pull you kicking and screaming back into the real world whenever you try to let your imagination roam.
In the night time, all manner of sinister noises that are hidden during the day are accessible to us, to help kick start our imaginations. Subtle things like the house creaking as it cools, or noises in the darkness outside. I myself have a fridge that thinks its a poltergeist, and makes ghostly noises during the night, as the gases creak about inside of it.
Noises like these fire up a writer's imagination, (being scared is a small price to pay). Finally there is nothing more damaging to a writer's productivity than people, because they always have something they want you to do. Other people are incapable of waiting – they see you at the computer and assume you're doing nothing important – because for them that novel you're working on is an intangible thing.
So writers have been turned into nighthawks by society, by the distractions of the day. We don't sleep at night, we don't dream at night, but we still journey the multiplicity of dream worlds. We are the vampires of the modern era, the Frankenstein (don't confuse the creator with the monster), the Jekyll and Hyde, the shadows that move in the night time.