Ours has a thick dish towel in one corner of his viv, and when we put him on that, we drape one over him to ensure it stays dark. I would not recommend having him sleep OUTSIDE of his viv in a towel/blanket. There's really no need for that. If he crawls out of the blanket, you then have a lost BD. At the end of the day, no matter how much we feel bonded to them, these are lizards...roamers. They are not human babies, or puppies. IMO, we should introduce them to our world as a human, but at the same time, respect theirs as a lizard. A healthy relationship with our BDs occurs when we find that balance between the two worlds. I know people want to bond with them, and you can...I have, and we have had him only 6 weeks. But there are so many other ways to bond with them than sleeping beside them, or keeping out of their habitat for overextended amounts of time. You can let him cuddle up against you in the evenings, sit on the couch and let him stare out the window, sit in the sun with him on your lap, let him roam around in one enclosed area (with small items such as legos or other hazardous swallowable items picked up off the floor), give him warm baths while talking to him, and watch him turn his head in the direction of your voice sometimes. In other words, do all the pleasurable things you want to do with him...from a lizards point of view, not a humans. I think he will be a much happier BD if you do. Wrap him in a blanket and sit with him to your and his heart desires BEFORE bedtime. But at bedtime, put him back into his viv. He will sleep more soundly that way, especially if you put him wrapped in a blanket inside his viv around the same time at night, routinely. And you will sleep more soundly knowing you don't have to look for him the next morning. There's always that chance that you will wake up, uncover the blanket to find it empty, and frankly, I would not take that chance.