>>4
Actually, looking for it during the day might be a better idea, since they're busy sleeping. Just look in a dark place around the area, because that's where they usually end up when they escape. Check all cubby holes, nooks and crannies.
Also, OP, make sure to put weight on the lid of your hamsterarium so it can not escape again. You didn't say what type of enclosure you have, but for me, I have an old fish tank that I keep mine in, and I use an old flashlight + its food reserves, and that keeps enough weight on the lid to keep him from breaking out.