Children as young as four are violently abusing staff up to "six or seven times a day", strangling, spitting and attempting to gouge the eyes of teachers and pupils, an education conference has heard.
Teaching staff have lifted the lid on the behaviour, reported at schools across the country, which is causing anxiety and concern among staff, forcing many to change the way they dress in order to reduce the risk of being hurt.
In one case, a pregnant special educational needs co-ordinator (SENCO) at a mainstream school in Shropshire described how she was repeatedly called into classrooms to restrain and deal with violent pupils.
Kelly Watkins, 38, told the NASUWT conference in Birmingham: "In the last two years behaviour in children has increased to an extremely violent level.
"As a SENCO, you have that magic wand to be called to a classroom to sort out the problem. As a pregnant SENCO I'm still called to the classroom."
Speaking after delegates agreed to call on the union's executive to consider industrial action to protect staff from violent pupils, Mrs Watkins, who is 18 weeks pregnant, described being "spat at, bitten and pinched" during her day-to-day work.
She also told reporters how a nine-year-old pupil tried to strangle her with her scarf.
"They pushed the scarf up and said they knew what they were doing," she said. "I had to get a colleague to go and get a pair of scissors to get the scarf off.
"Fortunately we didn't get to that point because I managed to get the scarf off. But it was a learning curve for me because after that it was take off anything - scarf, lanyard, cardigan, necklace - anything that might be used as a weapon."
Mrs Watkins, the only dedicated SENCO at her school, said she was repeatedly called to deal with a four-year-old boy who "scratched, gouged eyes, pulled hair".
She said: "It's increasingly hard to get children into the right provision because of the hoops needed to get them into the right place
"We are a very good mainstream school and we are getting a lot of children moved to us - equally, we are a mainstream primary school, not a SEN school.
"In Key Stage One (for children aged five-to-seven) it (violence) is getting more and more prevalent - more now than ever. The last two years have been the worst I've ever had in my (16-year) teaching career.
"If you haven't got the funding to buy in, you can't get diagnoses."
NASUWT executive member Russ Walters, presenting the motion, said teachers were "standing on the edge of a precipice" in terms of pupil violence.
He described how one colleague, an assistant headteacher in Bolton, was put in hospital for a week when he was head-butted as he reprimanded a 14-year-old boy.
He said: "Another school, a special school, has a problem with pupils spitting at the teachers. Management issued all the teachers with tabards so that when pupils spit at them it went on the tabards.
"I asked why they didn't put a bullseye in the middle of the tabard and go the whole hog.
"Behaviour is often the cause not just of Sunday night fear and anxiety, but every night, every day, every break time, every lunch time - concern and anxiety about going into situations.
"It fills me with dread to hear Newly Qualified Teachers talking about six or seven incidents during a day of abuse and the threat of violence and verbal abuse."
Chris Keates, NASUWT general secretary, said pupil behaviour was "one of the top concerns" that teachers raise about their jobs.
She said: "Evidence shows teachers are not receiving the support to tackle these issues.
"Where a pupil is known to exhibit violent and disruptive behaviour, a risk assessment should be undertaken and action taken to support the pupil to address their behaviour and to protect other pupils and staff.
"In too many cases no effective assessment is ever undertaken.
"Employers who fail to disclose safety information leave themselves vulnerable to legal challenge and industrial action, but more importantly they are behaving recklessly with the health and well-being of staff and other pupils and this simply cannot be justified."