How dark is dark enough?

When pondering my strategy for cycling my drys for breeding, I had a thought. How dark is dark enough? Should it be pitch black in the snake room at night for the whole night during cycling, or are minor interuptions o.k. And what about that blasted security light in the yard that is on all night every night? To what extremes do people go to in order to keep it dark enough, and keep interuptions of the dark period to a minimum?

As for me, I'm not too worried about it. I think as long as they go to sleep, and don't get awakened during that time, hey should be o.k. Right? I would think that their sleep cycle, coupled with the extra slow down in metabolism from the cooler temps is what does it. I know it may sound funny, but my Drys really do go to sleep at night. Especialy since they don't hibernate or brumate. I have a black lite on the ceiling in case I need to enter the room after dark. And if I need more light, I use a red flashlite. They never seem to now I am there unless I touch them. They apear to truly be asleep.