Teen boys come to class tired

I volunteer at a GED program in St. Augustine. The teen boys (not girls) aged 16-19 usually come to class at 8AM looking like they just got out of bed. It takes the teacher a significant amount of time to get them to focus on completing sample GED test questions. Girls the same age come ready to work. My grandson, who is in this demographic, behaves similarly. These teens are past puberty and have dropped out of HS for different reasons. Suggestions on how to get them to focus.