The association of teachers said increasing violent and disruptive behaviour among students has forced every two out of three teachers to quit the profession.
It has also been brought to light that pupils aged between five to seven have been expelled for attacking members of staff and that disruptive kids have been guilty of assault, bullying, threatening behaviour, theft and sexual misconduct.
Patrick Nash, the head of the charity Teacher Support Cymru, revealed it has become extremely important to combat the growing violent behaviour among pupils, as a single disruptive student can affect a whole class of students.
"Teachers are responsible for teaching not confronting violent, threatening or criminal behaviour," the Sun quoted Patrick Nash, as saying.
"This legislation must be implemented locally by school leaders, too many teachers we speak to are simply unaware it exists," he added.