I had the same thing happen, I forgot to re-latch completely and the next morning one of my babies had run away. I spent the entire day looking for her, the ENTIRE day. I checked behind the books on the bookcases, in my computer towers, in the futon, in the clothes in the closet just incase she somehow found a way into a pair of jeans or a jacket, I mean everywhere. Everywhere except a foam basket that was within 1ft away from her enclosure. I was working a few days later and heard a rustling, pinpointed that basket and just shook my head saying, "No freaking way." Well, to my embarrassment, there she was, not even a foot away from her enclosure.

Be persistent, I have read that if you get a shoe box and place a dead rodent in there, the smell will attract your lost snake. Simply cut a hole thats large enough for Auryn to enter, but not exit once she's eaten. I never tried that, so don't quote me!

Check everywhere, even the dumbest place that you'd never think she'd go.

Do you keep the door closed to that room when you aren't in there?