Research shows that they react against order, seek revenge and start blazes in schools to conceal a break-in or simply for fun.
The danger month is May when there is exam pressure, warmer weather and lighter nights so more young people are out and about. A second trigger time is at the end of the summer holidays.
A theatre-based national initiative called ACT (Arson Combated Together) was yesterday (Thursday) launched at Caldervale High in Airdrie to educate pupils about the damaging consequences of fire-raising. It will tour secondaries in the central belt before heading south to the rest of the UK.
Zurich Municipal, the insurance company funding the project, points out that Scotland accounts for a third of the total cost of school fires in the UK.
Caldervale has had three malicious attacks in the past 15 years, the last three years ago when a fire was started in a cupboard in the home economics department, which had easy access from the roof. The deputy head was the first to detect smoke and janitors put out the flames.
Four years before, an overnight break-in and fire in the same department caused major destruction. The cost of rebuilding, lost equipment and water damage ran to pound;60,000.
George Mackie, the deputy head, said the school took the issue very seriously and was proud to help launch the fire education scheme.
At St Maurice's High in Cumbernauld, a major fire last February destroyed half the extension after it began at 8.30pm. Sixteen of 60 classrooms were gutted and for three weeks younger pupils were bused to an empty primary while huts were put up on playing fields. Rebuilding will begin later this year at a cost of pound;2.5 million.
Peter Mulheron St Maurice's headteacher, said: "The cost of rebuilding is compounded by the loss of teaching resources and often there is substantial water damage. Fires can be a traumatic experience for staff and pupils."
The ACT initiative tries to get across the emotional, social and financial consequences of fire-raising and how it can affect communities, not just those directly involved in the school.