Sleeping in school

Kids should be able to sleep in school if it does not affect their learning ability. If you can sleep through a lesson and still pass the class or do the work, then teachers shouldnt care. Sleeping also starts arguments. The kids will say they were listening and the teachers will say the kids were sleeping. Some times it's hard to get to sleep at night or something may have happened. Would it be better to skip school or rest during first period? Sleeping shouldn't be a concern.