C.S.
Have you talked with their teachers? As a retired teacher who taught high school boys for 38 years, I can tell you that this is very "normal" behavior. The hormonal changes you describe cause most 14 year old guys to put school as a very low priority. That's when I saw many classic underachievers who were not working up to their potential.
Some techniques that you might try: assignment book which each teacher initials at the end of class each day. They show them to you when they get home. That way the grownups are aware, making it harder to say there is no homework. Plus the young men are responsible for writing down the assignments, helping them to remember that HW exists!
You can also email the teachers to ask for any insights they may have. Email is so much better than phoning because it can happen anytime.
If there is a particular class that is more of a problem, schedule a conference with you, the teacher, and the student so the 3 of you can come up with a plan for his success.
Maybe if they are spending lots of time on homework, they won't have time to get in other trouble. lol Taking away privileges like cell phones, video games, TV, etc. often gets their attention, too.