Q. My wife and I have a daughter, who is almost 7, a son almost 4, a 1-year-old son -- and a lot of bickering between the two older children.

They both have neighborhood friends and they usually don't bother each other when they're outside, but they bicker a great deal in the car and in the house -- especially in the early morning. Since I work at home, this is a real strain. How do I make them get along better?

A. Siblings are bound to get cranky with each other, especially at home. And it couldn't happen in a better place. Children need a safety zone where they know they'll still be loved, no matter what they do. And they'll do quite a lot before they grow up.

Fortunately, any misbehavior has its cure -- to some extent -- but you have to find the cause first.

Your son and daughter may act up because they're tired or hungry or because this is just their rather dreary way to entertain themselves when there's nothing else to do. Young children are rather like puppies. They like to mix it up, then play together, then sleep, then eat, then mix it up again.

Or your children may quarrel when one of them wants to play alone and the other wants to be part of the action. Block-building and Barbie games can be wrecked by someone who's three years older, or younger.

Generally siblings have more primitive reasons to rival, however. They may want more power in the family or more acceptance or, above all, more attention from their parents. One way or another, they're going to get it. Children would rather have negative attention than no attention at all.

Although some sibling rivalry is inevitable, even children with distinctly different temperaments can get along, if they're expected to negotiate and compromise with each other and be polite about it.

It will take observation and reflection to see what's gone awry. Keep an objective diary for a few days to see how the bickering starts, why it starts and what part you play. Once you analyze the problem, you can prevent much of it, although you'll never have around-the-clock bliss. Since your children squabble most at breakfast and in the car -- both times when you or your wife are around -- they seem to be looking for attention more than anything else. It's a habit that's quickly learned and often repeated, unless you block it with a few basic don'ts:

Don't take sides. The teaser clearly asks for the whine and the whiner always invites the tease, if only by being such a willing target.

Don't get involved unless you must. Children should solve their own problems if they can.

Don't let your children hit or insult each other.

Preventive measures help, too.

Give your squabblers little jobs in the house -- before breakfast or bickers -- or send your daughter outside to pluck the dandelion flowers so they won't go to seed, while your son is putting bread in the toaster. Busy children, like busy adults, get into less trouble.

And when the rules and the measures don't work, move in with some quiet discipline.

If your little boy whines about his sister's latest teases, say, "STOP! Is anyone hurt? Is anyone bleeding? No? Then I don't want to hear any more about it."

When they find out you mean it, they'll get quiet and grumpy, which you'll ignore, but wait a few minutes and then talk about something wonderful in their past or future, as if nothing had happened. Diversion is the name of this game.

You also say, "STOP!" if you're on the scene when the teasing first starts, but that's all you say. You don't lecture. You don't engage. You don't look furious. You don't pay them any attention at all. And when the teasing continues, either verbally or physically, you walk them both to their rooms, shut their doors and tell them to rest for 10-15 minutes, since they must be tired to be so crabby.

The car scene is more demanding. Give them each a damp sponge before you start, so they can clean whatever upholstery they can reach, and when they're tired of that, ask them to sing to you, or make up stories or play the kazoo. They'll think you're listening, even if you're not.

If the children fuss anyway -- and you can't ignore it -- you have to be stern: A driver shouldn't be distracted. Pull onto a side street, walk a few feet from the car and leave them inside to rue their ways for a few minutes. You then get back in the car when they look quiet, thank them for shaping up, and change the subject.

A few of these brief non-scenes -- and a lot more attention to the children when they're being good or fun or funny -- will make them bicker less and be better friends to each other. When children learn to get along with the family, they'll grow up to get along with the world.

Questions may be sent to P.O. Box 15310, Washington, D.C. 20003.