These days, high schools tend to defer to parents. If there's a family event, kids are pulled from school. If Bobby gets a bad grade, Mom launches herself into the teacher's office to give her a piece of her mind! Parents track their kids through the day, texting and calling multiple times.
College is different and not just because your kids are away from home, perhaps for the first time. It's different because your kids are expect to behave like adults. That means reading the syllabus, showing up for their classes, not making excuses for work not done, staying clean (yes, clean!) and sober (absolutely sober!) and taking real responsibility for their behavior and work.
Parents need to be aware that the "helicopter parenting" they have done for years not only isn't welcome by colleges, but most often is not welcome either by their kids. Besides being a time of academic preparation, the high school years need to a time when parents start to let go, and begin to hold their children to the standards of work ethic and moral behavior that will serve them throughout their lives. And that means starting to back off and let them suffer the consequences of poor behavior -- alone.
Listen to this 18 minute North Carolina Public Radio show with Professor Claire Bond Potter of The New School for Social Research for more on this topic: http://www.scpr.org/programs/airtalk/2014/08/07/38753/five-things-parents-should-talk-to-their-kids-abou/