One more thing to worry about, is their stuff safe? When they were at home you knew the valuables were safe, but now? Right up there with the call from my college daughter that she lost her phone, keys, student ID, (fill in the blank), is the call you get when they tell you someone took their cell phone, watch, or whatever valuable item your child has had stolen.
When my first child left for UM, I wavered between giving her space to find her way and wanting to hear all about her life at college. I had such a wonderful college experience myself, I toggled between exuberant excitement for her and overwhelming sadness for me.