Talking, whistling, groaning, writing notes, scraping chairs, calling out, tapping pens, popping gum, arriving late, getting up and walking around, not having a pen, not having the right books, not handing in homework, challenging instructions, cracking jokes, using a mobile.
As Ofsted pointed out last year, it is not violence that is the main behaviour problem in school but "persistent, low-level disruption of lessons that wears down staff and disrupts learning".
But despite a proliferation of tips and training on classroom management, nothing seems to get on top of it. Sixteen years ago, the Elton report on school discipline was saying the same thing, and last year's report by the government-appointed taskforce on behaviour, led by Sir Alan Steer, head of Seven Kings school, in east London, agreed.
Studies by the Institute for Public Policy Research show that bad pupil behaviour remains the main reason teachers quit, while the Association of School and College Leaders says that seven out of 10 heads now spend more time on behaviour issues than five years ago. Last autumn the National Union of Teachers felt the need to issue a charter of classroom discipline which included the right of teachers to be trained in the use of reasonable force to break up fights, and the right of teachers to personal panic alarms.
One reason for the continuing problem is that classrooms now include more children with learning and other difficulties. A second is that the tide is always rising. Schools might be getting better at handling bad behaviour, but the behaviour is getting worse.
Many teachers report that classroom silliness is getting more blatant and aggressive. Whereas once pupils might have simply scraped their chairs around on the floor, today they turn them around and sit with their backs to the teacher. Mutterings of "You can't make me!" are now common, and more and more pupils seem to think it is their right to slurp and chew their way through lessons.
"One thing I've noticed is that children don't seem to have the same understanding about how to behave around people's property any more," says Gary Monger, who teaches science at Gleed school, an 11-16 boys' school in Spalding, south Lincolnshire.
"They'll go into someone's pencil case and take something without asking, just because they need it at that moment. Then that person finds out, and there's all kinds of trouble that you have to deal with.
"Children do things with more attitude, they're more bolshie and more likely to be pushing the boundaries," says Louisa Leaman, a teacher and author of Managing Very Challenging Behaviour and other books on classroom management.
She says it is essential to step in early and defuse things without confrontation. "But in the modern inclusive classroom it can be hard to find the time to do all the right things. The trouble is, you can't cut corners in behaviour management. You have to devote attention to it, and not see it as an added extra."
But new teachers are not arriving in schools well-trained in class control.
Graham Willson, head of GLD Training Associates, a company which has been trialling a new training course for teachers in south London, says that of the 65 newly-qualified teachers being mentored in Bromley few feel they have been given worthwhile training in the area and many want help. His one-day training teaches an American system of verbal and non-verbal cues to give people more "charisma, magnetism and influence".
"For instance, you learn to stand with high expectations of listeners, with your feet apart, toes pointed forward, and your hands at your sides or gently held in front of your tummy. It's not just body language, there are 6,000 external cues which have been extensively researched. When I teach this to the newly-qualified teachers they immediately say, 'Oh, I can use this in the classroom'."
Over the past three years the Government has spent pound;500 million on behaviour. It has set up behaviour and education support teams as part of its wide-ranging behaviour improvement programme, which aims to tackle both poor behaviour and truancy. It also put into last week's Education Bill a clear legal right for teachers to discipline pupils. But everything comes down to how schools and teachers tackle daily problems.
Anne Larg, an experienced secondary maths teacher who has taught in a tough, inner-city school with a good discipline policy, and a quieter, country school with a less effective policy, says it was much easier to maintain good behaviour in the tough school. "A school has to have a good discipline system, with positives as well as negatives, if it is aiming to improve all the low-level nonsense that is going about."
For Catherine McLelland, who works in a Glasgow secondary school, the things that would make a difference are "smaller class sizes, a more consistent approach from senior management, and the availability of reliable support staff on a regular basis."
She also notes that pupils are coming up from primary school with no expectation of having to work silently on their own. "So perhaps there needs to be more consultation about these kinds of expectation between primaries and secondaries."
But the biggest problem in dealing with classroom discipline is that there is no magic fix. Teachers have to do hundreds of small things every day.
Sir Alan Steer says, it is a question of "doing the obvious and doing it regularly". While John Bayley, an education consultant whose fly-on-the-classroom-wall programme Teaching With Bayley, is the hit of Teachers' TV, points to Ofsted's 2005 report Managing Challenging Behaviour. "Really, that says it all."
The report stresses the need for teachers to teach lessons that engage children, to tackle pupils' literacy and communication problems, to be consistent, and to praise more than blame. It also emphasises the need to get on top of small problems before they become bigger ones. In the classroom this means starting as you mean to go on. Gary Monger says "You have to start firm and lay down the lines quite firmly. For instance, in my subject, they have to know you want all diagrams drawn with rulers and pencils. Later you can ease off." But this can be tricky for new teachers, he points out. "The last two NQTs I had, had to re-establish themselves halfway through the year."
Dame Maureen Brennan, head of Hillcrest school and community college, Netherton, in Dudley, who turned around behaviour at what was once an unruly school, says that behaviour issues can only be tackled once a settled staff is in place. After that, measures such as getting rid of bells, meeting and greeting pupils at the classroom door, having seating plans for every lesson - including a boy, girl arrangement for troublesome classes - and walking round the classroom all help keep control.
"But for low-level disruption, the key is to keep it low key," she says.
"Instead of stopping everything to deal with it, have a quiet word in their ear. And the quieter the voice, the harder they have to work to hear you.
If you engage with them, what you're doing is teaching them how to disrupt the lesson. You're rewarding them, because stopping the boring lesson is exactly what they want. So if someone is tipping their chair back, you don't say, 'Do you realise how dangerous that is?', and invite a discussion. You maybe use a little expression such as 'four on the floor'."
Today's children have more options and expectations than children did in the past, she says, which can make them more demanding to teach. "In the old days teachers weren't competing against the Discovery Channel."
Today they have to earn respect, and be sure they are offering lessons that are worth listening to.
Oh, and smile, she suggests. Children do not like being taught by miseries.
Classroom control: the rules
We asked visitors to The TES website (www.tes.co.uk) for advice on class control. Suggestions included: Primary schools
* Set classroom rules - hands up, eyes on the teacher.
* Use brain gym to get pupils focused in the morning.
* Make starter activities easy and achievable to settle everyone down.
* Appoint a "hurry up" monitor.
* Insist pupils come into the classroom in an appropriate manner.
* Start lessons with "a quick bit of introductory copying".
* No pen? Tough. Let them sweat when no one will lend one.
* Preface remarks with instructions about whether they can talk or not - "work in silence" or "confer quietly".
* Tell pupils exactly what you object to, why it's rude, then point out when it is happening and who is doing it.
* Go for zero-tolerance discipline: allow no excuses.
* Work on self-control with your class.
what it is and how to do it.
* Abolish compulsory schooling after 14 - return to apprenticeships.