My son has been auditioning since birth for the role of barnyard rooster. At sunrise, his eyes snap open like window blinds in a cartoon, and he hits the floor running. His mouth, generally.
But rousing my daughter is like trying to bring someone out of a coma. Her breath is shallow and hot. Saying her name repeatedly, I rub limbs that feel as if they have had the bones removed.
And this is the best part of summer vacation: For 12 weeks, I will not have to deal with my children's idiosyncratic sleep patterns. Come June, the arguments over going-to-bed and getting-up are as tired as I am.
If they knew what was good for them, children would sleep.
Their mood and their schoolwork would improve, along with their relationships with their parents.
But children are overbooked, or they are afraid they will miss something good, or sleep is something else they want to argue about. Soon, bedtime rituals become bedtime power struggles.
"If someone told me to go to bed, I would say, 'Where?' Not, 'No,' " says my sister Cynthia, who argues about bedtime four times each night.
Like most mothers, I send my kids to bed when I am tired. But there is an intimacy in our relationship with our children that allows us to know exactly how tired they are. Kids don't have to be punch-drunk for mothers to know they need some sleep. We can see it as clearly as the fuel gauge in the car.
But to children, sleep is playtime lost forever. It takes real maturity for a child to know the world will be a friendlier place if he just takes a nap. My daughter, in a harridan's rage, has often sobbed herself to sleep -- very quickly, I might add -- over the injustice of an imposed nap. When she wakes, we like each other again.
"We are not fighting about friends or schoolwork or wanting to hang out at the mall," said my sister. "We are fighting about bedtime. I look at my son, and he can barely stand erect and his eyes are so ringed with purple that it looks like he's been punched in the face. But he spends every bit of energy he has left telling me he isn't tired."
This is because children do not know what sleepy feels like, says Dr. Richard Allen, assistant professor of neurology at Johns Hopkins Medical Institutions and co-director of the Sleep Disorders Center there.
"Children are not aware of how tired they are. We know it, because they are irritable. But they will go until they drop because they don't have the signals we do. Only later, in adolescence, do they begin to experience adult levels of sleepiness," Dr. Allen says.
Young children and preteens need between nine and 10 1/2 hours of sleep a night, sleep researchers say, and teen-agers not much less. But working parents, late dinners, sports and homework erode bedtime.
Naps or early bedtimes are considered an insult by the emerging teen-ager, setting the stage for arguments.
"They really are resistant to sleep at this age, and I have never understood it," says Dr. Allen. "They get anxious at bedtime, and I think that is part of the problem. The best thing to do is to maintain those bedtime rituals later in life. Quiet them. Calm them."
Dr. Allen says that preteens feel most like a child, most vulnerable, at the end of the day. Fatigue makes them babies again, and they need the comforting bedtime rituals of snack, story and snuggle that we'd thought they'd outgrown.
For teens, the problem is compounded by hormone changes that make it physiologically impossible for them to settle down to sleep early. To their parents, it seems as though they are being manipulative or rebellious when they are simply on a biological version of West Coast time.
Sleep experts will tell you that the practice of opening high schools earlier than middle schools, which are opened earlier than elementary schools, runs precisely counter to children's physical needs.
And parents are equally misguided to castigate their teen-agers for sleeping late on weekends. They are not lazy -- they are tired, and they can, and do, make up for the lost sleep of the school week.
Still and all, it is remarkable how a fast a child's sleep needs can change. The boy you can not wake Monday can spring from his bed for Saturday cartoons.
"Jack never complains about getting up at 4 a.m. to go crabbing," says a friend of her 11-year-old. "But 7 is too early for school."