Summer's over, and for parents, that news can be both bad and good. Many now face the dreaded morning task of rousting bleary teenagers out of bed and hustling them off to high school on time. For the parents of college students, though, the return of the school year brings blessed relief from a peculiarly modern worry and annoyance -- kids' ever wilder nocturnal habits. No longer -- at least until the next college break -- will these bewildered parents have to pose the nightly question: "What could you possibly be doing up until 4 a.m.?"

Shakespeare called sleep "nature's soft nurse" and "chief nourisher in life's feast," but try telling that to today's high school and college students, who have embraced the night with a vengeance. More and more, it seems, teenagers and young adults are ignoring the Bard's wisdom to deprive themselves of slumber's benefits -- to the detriment of their academic performance as well as their physical and psychological well-being.

Even many high-schoolers are routinely up until 1 or 2 a.m. -- yes, on school nights, too -- while the college all-nighter that was once a rare feat of fortitude has

become, yawn, routine. College, in fact, seems to turn kids into veritable night stalkers, much to their parents' horror. "When they come home, kids act like they're living in Las Vegas," one mother told me. "They go out at 11 p.m., sometimes wander back home a few hours later and then go out again. The doors are opening and closing all night. They're living vampire hours."

Parents report getting home from work at 5 p.m. or later and walking into the kitchen to find their kids just getting up from a full day's sleep and eating a bowl of cereal, preparing to start the night rounds all over again. Still others say their kids never make it home -- they just flop at a friend's house after a night of carousing. It makes for some tense relations between generations that have completely differing notions of what the night is for.

Eileen Ahern, whose 21-year-old daughter Catherine was in my English class at T.C. Williams four years ago, says it took time to get used to Catherine's summer night sojourns whenever she came home from the University of Virginia. "She'd tell me around 7 that she was going out and I'd assume she'd be leaving in an hour," she said. "Then I'd learn that her friend wasn't picking her up until 11. I had to trust her, but I couldn't sleep until she got home -- sometimes at 3 a.m." Which may make Ahern one of the lucky ones.

My father used to say that nothing good can happen after midnight -- an uncontestable truth from his perspective as a doctor in a small town near Buffalo, N.Y., who often had to get up at 2 or 3 in the morning to attend to bloody revelers who had smashed their cars or snowmobiles or each others' skulls. His grandson has a slightly different perspective on the night life. "The truly cool don't even want to be seen in a club or bar until after midnight," says my son Neil, who, at 24, is now a semi-reformed night creature. "They'll stay until about 3:30 -- then it's out to eat or off to an after-hours club like Five on Connecticut Avenue or Fur in Northeast."

These late, late nights are a relatively new phenomenon. When Washington lawyer Stu Long opened the Hawk 'n' Dove restaurant on Capitol Hill in 1967, college students would start coming in at 8 or 9, he told me. "About 10 years ago they started coming in around 10 p.m.; now they start showing up between 11 and midnight," says Long, who recently added an upstairs room for dancing to accommodate the influx of late-night college kids and keep them separate from the older, earlier revelers downstairs.

Long sees lots of kids who have spent a semester or two in Europe, where they feel freed from constraints like the drinking age and get accustomed to parties that start late and go long, and he thinks they bring the habits home, contributing to the late-night frenzy. Northwestern University sophomore Alison Lehner, who spent a year in Seville after graduating from T.C., agrees. In Spain, "it seemed like everyone from 15 to 35 stayed out all night." People meet for drinks at midnight, she said, then go to the discotecas at 3, then stumble home at 5 or 6 and sleep into the afternoon the next day.

Northwestern hasn't quite reached that level of revelry, says Alison, but staying up until 3 and sleeping past noon is commonly accepted. "The campus is dead at 10 on a Saturday morning, and the dining halls don't open for breakfast until 11:30 on the weekends," she says.

Several students I talked to think colleges encourage the late-night activity by scheduling so many classes late in the day. U-Va. senior Catherine Ahern told me that this year her earliest classes are at 11 a.m., and some days she doesn't have a class until 2. But this could be the proverbial chicken-and-egg situation: Maybe colleges started scheduling classes later in the day because so many students were staying up so long and missing early-morning courses.

Whatever the truth, the ultimate effect is anything but positive. "My first year at U-Va. I would stay up until 4 or 5 in the morning talking to friends, chatting online," Ahern told me. "Then I would take naps in the afternoon. My body became exhausted and I got really sick. My second year, I made sure I got the eight hours I needed." But she says she knows plenty of students who get four or five hours a night for a couple of weeks, then try to catch up by sleeping through a weekend.

It's not just all-night outings that are robbing kids of routine rest. Caroline Moncure, who graduated from William and Mary in May, sees the Internet as the biggest source of sleep deprivation for college students. "I've seen girls who became obsessed with instant messaging and online shopping, and online gambling is really big with boys," she says.

The most alarming thing, though, is that the vampire life doesn't start in college. Many kids bring the habits of nighttime excess with them from home. Mary McCarthy, a guidance counselor at T.C. Williams, told me that lots of high school kids stay up until 1 or 2 in the morning instant messaging, talking on their cell phones or surfing the Web. Then, "when they're late for morning classes or just miss them, parents come in giving the excuse that their child has a sleep disorder," she says. "Instead of taking away the cell phone at night, or cutting off the Internet, many parents are putting their kids on prescription sleep aids like Ambien." McCarthy says there are sleep-deprived kids at school getting through the day on the caffeine in drinks like Red Bull, Jolt and triple espresso shots at Starbucks.

It's a source of anxiety for lots of parents, but too many seem powerless -- or unwilling -- to do anything about it. Many high school kids cloister themselves in their "wired bedrooms" like animals in a den. They have cable TV, computers, cell phones, video games and every other source of amusement at their fingertips -- all of which they think they have a God-given right to. As soon as they get home from school, some retire to their bedrooms to begin the night's amusements, coming out only for dinner, which they often carry back to their rooms.

I've taught girls who would record the early afternoon soap operas, which they would watch late at night after their regular TV fare; I've had boys who would stay up watching the NBA games from the West Coast until 1 a.m., and others who would stay up until 3 trying to get to the next level of some video game. The wired bedroom works well for parents who want to keep their kids pacified and out of their hair, but it offers too many nocturnal temptations for even the most disciplined of students.

L.J. Harbin, who graduated from T.C. in June, says that after he got home from his job and finished his homework, it would often be 9 or 10 p.m., and he wouldn't want to go to sleep. "I'd relax by getting online and talking to friends, playing a video game or watching a movie on DVD. Several times I went to school without any sleep at all."

I've taught a number of boys who were chronically late to school. There were others whom I would constantly have to admonish to "get your head up" as it drifted to the desk. Some guys told me their trick for sleeping in class: Hold your head up in your palm, turn your face away from the teacher, close your eyes and doze. That sounds amusing, but it really isn't good for learning.

And now the problems are seeping down to even younger age groups. Bethesda adolescent psychiatrist Lawrence Brain says that parents of kids from middle school on up are frustrated by their children's use of electronic media, especially at night. "The three big things that cause the fights are the video games, the cell phones and instant messaging. If parents don't give the kids these things, the kids complain that they'll be isolated and their social lives will be ruined. But once they give in, the parents feel they have little control. Kids get used to so much stimulation they can't be by themselves anymore. If they're using cell phones and IM-ing at night, they get so stimulated they can't sleep," says Brain, who sees adolescents who go to bed at 1 or 2 a.m. and get up at 6 a.m. for school.

So are our kids wired to be up all night, or is our wired world just keeping them up? It's hard to separate the two. Even the most responsible students have a hard time getting enough sleep during the school year. T.C. newspaper editor Sarah Schaffer told me that over the summer she got between eight and nine hours of sleep a night, but during the school year she can only manage about six. "I feel I can do my best work later at night," she says. "I often stay up till 1 working, but then I have to get up at 6:30 and my brain isn't functioning until 10."

Sarah's experience bears out the research of Brown University psychologist Mary Carskadon, who told me that "adolescents need about 9 hours of sleep a night. Adolescents who haven't had enough sleep are at their absolute wretched worst in the morning." Carskadon also says that at pubertly, adolescents under go a "phase shift" and start falling asleep later at night than younger children."

So okay, you can't browbeat teens into going to sleep early. But do they have to stay up all night? I've been thinking about doing my part to help reverse the vampire lifestyle. I just may go back to teaching James Joyce's "Portrait of the Artist as a Young Man" and Virginia Woolf's "To the Lighthouse" -- two novels I stopped teaching because students reported that both books put them straight to sleep after just a page or two.

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Pat Welsh has taught English at T.C. Williams High School in Alexandria for more than 30 years.