Ask most teachers what they fear most about bad behaviour and they’ll probably mention fights, knives and chairs through windows. But ask them what the most common bad behaviour they experience is, and they’ll probably talk about calling out, not bringing pencils, chatting at inappropriate times. In other words, what is normally described by the Department for Children, Schools and Families as low-level disruption.

Low level sounds insignificant and harmless, like low key or low profile. Dream on. Low-level disruption is like Kryptonite for the well-planned lesson. It’s like a woodpecker boring a hole in your head with a toffee hammer while wearing a Pete Doherty mask. It’s that annoying. And it’s that insidious. By itself, it is disrespectful and distracting. Left unattended, it erodes the sharp edges of your lessons like a river rubs a path through a mountain, grain by grain. It’s the thin end of the wedge.

Why so serious? Because low-level disruption is what pupils do instead of learning. It’s a classic diversionary tactic where the sole function, by intelligent design or dumb malice, is to turn your lesson from a symphony to a cats’ chorus.

Apart from the fact that it slows you down because of the time it takes to deal with it, it contributes to a disintegration of your classroom respect, therefore control, and therefore authority to lead and to teach. One day they’re chatting over your PowerPoint, the next they’re file- sharing on their iPods during their Sats. And if they won’t follow behaviour guidelines on the small stuff, can you expect them to follow the big rules? Here are some pointers:

Have clear guidelines

At the start of the year, take time to explain precisely what you expect of your class throughout the academic year. That could mean something stuck in their books; it could be a poster on the wall; it certainly means a verbal explanation, where you dispel any ambiguity about your vision.

If it seems unnecessary to explain that gargling fizzy pop isn’t quite cricket in your lessons, rest assured that at least one of your pupils will not be aware of this until you explain it.

Get tough in the first few weeks

This is why there are sanctions in the Army for having unpolished shoes or messy kit. It’s not that the Ministry of Defence thinks that a well turned-out soldier will impress the enemy and make them pack it in, but the fact that if a soldier is obsessing about such detail, then they really ought to have oiled their gun. So go in like the SAS for details, even if it seems like a pain.

Nip it in the bud

Before a pupil starts chatting, or rocking on their chair, or whatever it is that presses your buttons, as a precursor to regular full-fat low-level misbehaviour. These micro-gestures will include looking around, drumming their fingers, making repeated eye contact with others. Gently reinforce positive behaviour by drawing attention to their tasks, rather than by making a fuss.

Get them on task

One of the simplest techniques for restoring and reinforcing good behaviour is to focus on what they should be doing, rather than what they shouldn’t. Actually this is pretty good advice for just about any influencing technique, as it shows you display dominance in the relationship. If you start going mental and shout about drawing on the desk or face-pulling, then you’re getting drawn into their behaviour, even if you’re just responding to it. Instead, set the agenda by saying: “Let’s see those first tasks done in the next 10 minutes,” or “What should you be doing next?” It’s polite, it’s task-orientated, and it’s on your terms.

Tacitly ignore it

This piece of advice is so dangerous it should be in a cage and only viewed indirectly via a mirror. Sometimes, and only sometimes, you should actually ignore a low-level disruption. But when? When tackling the disruption would lead to an escalation of disruption by itself, or risk massive disruption that would outweigh the benefits of squashing it. For example, one of my best pupils got into a fit of the giggles recently, but because I understood the context of her “misbehaviour” (which could have been construed as disruptive by another pupil) I simply cleared my throat melodramatically, smiled and moved on. The class understood the significance of the cause and effect, and no more needed to be said. Similarly if a pupil goons about during a test for a nanosecond, then looks guilty when they see you glowering, it could be argued that no more should be said. Like I say, this one is delicate, so tread carefully, or you can be accused of inconsistency.

Use humour

This is probably even more dangerous than the last point, mostly because many teachers lack levity in their lives. One of my Year 10 boys (who was no stranger to the biscuit tin) once disrupted my Sacraments lesson by loudly proclaiming that he’d been baptised recently. Before my disciplinary machine roared into life, one of his equally roguish colleagues quickly quipped: “Was it at SeaWorld?” Job done for me, he slithered back into his surly cave.

Distract them

This is similar to getting them back on task, but is useful when they are starting to get so far from the task they could barely see it with the Hubble Telescope. Suddenly bring up a new topic in an interested and excited tone (for example, “Who saw Big Brother last night?”) and when you get the inevitable deluge of attention from your little goldfish, steer the conversation quickly back onto the topic at hand (“Should this person have acted the way she did?”) before then directing them back directly onto the task (in this case, Applied Ethics). Sometimes disruptive behaviour is the pupil’s way of telling you they’re bored with the lesson. Of course, they have a responsibility to you, the class and their education, but you also have a duty to stir their enthusiasm.

Really distract them

Pull out a marker pen and suddenly say: “Everybody look at the pen.” You will have everyone’s attention for exactly three seconds. After that, you’re on your own. I warn you, this will work exactly once, unless you are teaching an exceptionally slow-witted group.

Tom Bennett is head of religious studies and philosophy at Raine’s Foundation School in Bethnal Green, east London

What is low-level disruption?

- Begging for pens and equipment.

- Arriving late.

- Chatting constantly.

- Shouting the answers out.

- Pupils trying to be funny (as opposed to teachers trying to be funny, which is just toe-curlingly embarrassing).

- Tapping, rocking, rapping or typing.

- Anything involving make-up or telecommunication equipment.

- A million other things. Any behaviour that impedes learning, as defined by you.