My snakes are in a seperate room, I had a big girl get out the other day, and wouldn't you know it i had let the room door opened, I searched all the obvious places, no luck. I figured since I'll be moving in the next 2 weeks that she'd turn up. Well I found her peeking from under the rack.
I own a fiber optic snake with camera/light attachment which makes it easier to search small dark places.