First it was Ruby’s new gel pen. Then Jordan couldn’t find his favourite rubber. In the same week, we found we were missing Shannon’s 50p and Caitlin’s pencil case, while the leftover lollies from Jack’s birthday had somehow walked off on their own. Something was rotten in the state of class 3B and it was up to me to get to the bottom of it.

Light-fingered youngsters are a not uncommon problem for most primary school teachers. When 30 children are put in the same space for a year and made to share cramped cloakrooms and stationery boxes, for some the temptation to purloin a shiny pen or slide a chocolate biscuit out of a lunchbox is just too much.

It is important not to judge stealing in young children in the same way as you would in adults. A five-year-old who pockets a few coloured pencils isn’t necessarily destined for a life as an international jewel thief. Children take things that don’t belong to them for myriad reasons, and once you’ve identified the culprit your next step should be to figure out what is behind their behaviour.

Children who repeatedly steal food may not be being fed properly at home. Others may steal “trendy” items to try to fit in or because another child is making them do it. In the case of very young children, they often see something they want and simply put it in their pocket. I once had an arrangement with a parent who, when I saw her in the playground, would discreetly hand over the coloured pencils her daughter had “borrowed”.

Finding the culprit shouldn’t tax your detective skills too much. Once the stealing starts, you can usually spot the guilty party pretty quickly, but the golden rule is never to accuse a child of theft unless you are 100 per cent certain that they are the culprit - and you can back it up with hard evidence. If I have a problem with stealing in my class, I take the following steps to address it.

Identify the problem

It may be blindingly obvious to you, but some children in your class may genuinely not know that stealing is wrong. I have come across children for whom theft was less of a moral issue and more a family business, so the need to reiterate that it is always wrong to take something that doesn’t belong to you (just as it is never OK to tell your older brother where the school’s new laptops are stored) is vital. The beginning of the year is a good time to talk about respecting other people’s property, looking after your belongings and not bringing in valuables.

Encourage sharing. Some children steal things so that they will feel accepted by those whose parents buy them fancy stationery. But urging those lucky children to share often eliminates the need for this.

Make it a whole-class issue

The odd missing pencil needn’t have you calling a council of justice, but once a definite pattern of theft has been identified it is time to address the problem. This is best done as a whole class. Explain to the children that things keep going missing, remind them that taking others’ belongings is always wrong and stress the need to be vigilant. You can also give the culprit the opportunity to put the stolen items back, no questions asked.

Involve the rest of the staff

If you have a student who is persistently taking things that do not belong to them, this needs to be shared with the rest of the staff. Let your senior managers and school leader know and make sure that other staff know which child is doing it. That way there will be plenty of trained adult eyes on the child when they are hanging around cloakrooms.

Stop and search

Sometimes the best way to put an end to the problem while also demonstrating justice being done is to search bags and trays. Even if you know beyond a shadow of a doubt who is responsible, search the entire class. Make sure another adult is in the room while you get the children to stand in silence and empty their trays or hold their bags open in front of you.

If you find what you are looking for, it’s best to play it down: young children often have a great taste for vigilante justice and there is nothing to be gained from a chorus of “Thief!” from the whole class. If I find a missing item in a child’s bag, I often talk loudly about how it must have got there by mistake and emphasise the importance of everyone looking after their belongings. If you feel it is necessary, you can discuss the matter with the child later. And be ready to spot and stamp out any playground taunting about the incident.

Most importantly, do all you can to help the child who is stealing to realise that it is wrong. Until you get there, it’s probably best to keep one hand on your wallet.

Jo Brighouse is a primary school teacher in the Midlands, England

What else?

Try this PowerPoint presentation in an assembly on stealing and its consequences.