Yup, that. One of my friends has an uncle that had a Burm that got loose. Years later as they were moving out they found it, still alive, curled up in one of the heating vents in the basement. Must have just been living off of any wild visitors (hey, free mouse traps!) since they'd given up finding it long ago. Don't stop looking, and remember to check EVERYWHERE, including places you don't think he'll fit. You'd be surprised.