The yellow school bus is more than a ride to and from school. It's a rite of passage. From puppy love to fistfights, nearly every kind of pre-pubescent and adolescent social -- and antisocial -- behavior takes place daily inside the confines of school buses.

At the request of Prince William County School Board member Kathryn Perrin (Brentsville), school officials recently surveyed 139 county school bus drivers and 45 school administrators to test the climate on the county's approximately 800 bus routes. They wanted to find out whether students' behavior created a safety problem.

From the responses, the climate seems, well, turbulent. "Partly sunny with occasional tornados" might best describe the atmosphere. Although most drivers said discipline is not a major problem on their school buses, mischief-making is the modus operandi for many children. And they are an inventive lot.

"If there's something that can be done, we've probably had it on our buses," said James Bettis, director of transportation for the schools.

Middle schoolers appear to be the worst offenders, according to the survey, their most common transgressions being tampering with bus equipment, littering, back talk, fighting and using bad language.

Several drivers and administrators suggested special classes for drivers in how to handle discipline among the sixth-, seventh- and eighth-graders.

Elementary school children specialize in fighting and being noisy.

By comparison, high school students seem a sedate lot, but they too are loose with their language, drivers complained.

Have you ever sat in a car behind a stopped school bus and watched it bounce, even at a standstill? Consider these descriptions by school bus drivers of what goes on inside: children throwing things and spitting on cars and people from the bus windows; poking their arms and heads out of windows, hanging over the seats and screaming at each other, picking on others, mobbing the bus doors before the bus stops, gesturing to drivers behind the bus, drinking sodas and "engaging in horseplay."

Mischief aboard school buses knows no boundaries of geography or intelligence. Four years ago, a bus full of ninth-graders was pulled over on Interstate 95 by three state troopers, blue lights blazing. Unbeknownst to the driver, her charges, all Prince William County freshmen at Thomas Jefferson magnet school for science and technology, had put a sign in the rear window saying "Help us. We've been kidnapped."

Prince William, spread over 345 square miles, has one of Northern Virginia's most extensive school bus operations, covering 25,000 miles per day and serving 28,500 students in the morning and again in the afternoon. "Double that number, and you have double the opportunities for mischief," said Bettis.

But Bettis said student behavior is better than it used to be in the days when the county had a rural school system and it wasn't unheard of for students to pass around a bottle of booze on the bus. Once, years ago, a student released a snake on a bus, according to Bettis.

Discipline is a safety issue with Bettis. Too much noise and carrying on can distract a driver and cause an accident. Safety is the issue with drivers as well, and although seat belts have never been proven as a safety item on school buses, many drivers favor them.

"Seat belts would keep students in their seats," said one driver.