You said that you thought you heard him a few times during the night, but he wasn't in his bed. Is it possible that he could have been under his bed the whole time?

I don't want to alarm you, but there are a lot of chemical changes occurring in kids during adolescence and sometimes depression or other mental health issues arise at this time. Have you seen signs of paranoia, or sensing that he believes things that aren't true?

It may be that he was out all night, but keep an open min that he might need some medical help.

take care,

kate