When Peter was 6 he smashed a bike helmet into another child's face.
That school year he caused 180 separate incidents where he had to be taken home or dealt with.
"You've got no idea how aggressive he was," says his grandmother, Sonia. "His face would be distorted like the Incredible Hulk and that would be over the smallest thing. Someone would just have to poke their tongue at him.
"Even at 4 1/2 years of age, when he hit someone it wasn't a slap, it was a full-on beating. That's how much anger and aggression he had in him.
"Every time the phone rang I would dread seeing the name of the school and whenever I did I nearly cried. I'd worry about what damage he'd done to some other child. I didn't want him to get a reputation."
Sonia is raising Peter and three siblings because their mother is a meth addict. To protect their reputation, we've changed their names.
The children were living with their mum and the father of the three youngest. The adults were violent to each other. Their home, says Sonia, was "the worst pit that kids could live in … maggots, shit, the lot".
Now they've got food, clean clothes, love.
Things are looking up for Peter. Now 7, he's five months into medication often used to treat attention deficit hyperactivity disorder.
"Don't get me wrong," says Sonia. "He's not fixed. I think that medication has improved his aggression a lot and that was my main concern. But he still can't keep still, focus, pay attention."
The trend of grandparents caring for grandchildren has been widely reported. The impact of meth exposure on kids is less known.
Some people refer to them as P babies – innocent victims of New Zealand's 20-year methamphetamine epidemic. It's reasonable to think those children born to meth-using mums in the early days of the crisis will be leaving home, starting work.
A major research project at the University of Auckland has found delays in cognitive development and behavioural problems that may continue to inhibit learning.
Yet there's no firm handle on the scale of the problem.
"In terms of behaviour and probably later mental illness," says project director Trecia Wouldes, "it is a really big public health issue because conduct disorder is a really big deal".
Sonia thought taking on her grandchildren would be temporary. That was more than six years ago.
The mother of three adult kids had to give up her job at a kidswear store ("I love talking to people") and become a parent again.
"It's taken a big toll on my life."
Sonia, 57, was doing plenty even before Child, Youth and Family (CYF) stepped in.
"I'd go and see the kids before work, I'd see them after work, I'd take them for the weekend. I'd go to work exhausted and worrying about them."
When CYF asked family if they'd take the children, Sonia was the only one to offer them a home.
"It was a decision that was out of my hands really but it was a good decision in the end."
Sitting in the tidy garden of her four-bedroom home on a quiet suburban street in Auckland, the 57-year-old says the children were affected in different ways.
Being the youngest, less than a year old when she took him in, Peter probably needed the most help.
"I've always believed his behaviour is some sort of chemical imbalance. You can't smoke all that P while you're carrying kids and have it not affect that child.
"But every time I would mention the chemical imbalance to the professionals they would say the same thing – there's no research, nothing's been proven. They put it down more to the fact that when he was a baby he was always left on the couch."
Peter had bad eczema too.
"He itched from head to toe and whenever I went over there he was in a onesie that would be soaking wet with urine or soaking wet with shit, neglected on the couch and itching.
"When I got him I bathed him all the time, creamed him all the time. In that first nine months, when he had none of that done, imagine being itchy as hell and not being able to scratch yourself and not having any mum pick you up and comfort you or cream put on you or a bath."
Meth's impact on children like Peter is being studied at the University of Auckland. Associate Professor Trecia Wouldes is leading a long-term study collecting health and development data on 107 children born to women who used while pregnant.
Predominantly from lower socioeconomic backgrounds, their development is compared to another group of children whose mums reported and tested negative for methamphetamine use during pregnancy. These mothers were selected based on a similar level of education, ethnicity and socioeconomic status.
Active since 2005, it's now the only longitudinal study in the world. Wouldes and her team have checked in at key milestones – birth, one month, one year, and so on.
The research shows health and development may suffer from prenatal exposure to P, but also from the impoverished environments children grow up in. Those environments are often characterised by domestic violence, poverty, ongoing drug use in the home and maternal mental illness.
There's evidence that meth does affect brain development, but the effects are often subtle, affecting early neurobehaviour. This includes problems settling into routines and being more irritable and difficult to handle during the first couple of months.
Wouldes has also found delays in motor skill development, which may include lags in learning to crawl or walk and to hold or pick up objects over the first three years of life.
Delays in cognitive development, such as problem-solving and remembering rules, and behavioural issues became more apparent from 4 ½ years. Particularly among boys. Especially Māori boys.
At 6 ½ there were signs general memory is affected, with an expected knock-on effect on learning that could be compounded as children progress through school.
"This is the first time we're seeing delays in cognitive development for all of the exposed children," says Wouldes.
"We're not finding irreversible brain damage, which I think a lot of people expect. It's behavioural problems that interfere with learning. And the behavioural problems might be a combination of exposure to drugs and the home environment.
"If it's entrenched in a 5- or 6-year-old, those are the kids that are going to be at risk for having aggressive behaviour or conduct problems that go on to be associated with criminal behaviour.
"But it's not something that can't be remedied by being in school and getting support."
Peter is one of the lucky ones.
His primary school spends a chunk of its everyday budget on a dedicated unit for a handful of pupils – all boys - with significant trauma, including exposure to meth.
The principal is clearly invested, emotionally as well as financially. Yet such is the stigma around meth he doesn't want the school identified lest it put off prospective parents.
"These are not bad kids," he says. "These are kids that are just totally wired and they're wired to run, they're wired to protect themselves but they don't know why they're doing it.
"They'll hit. One of the boys punches like a man and he goes straight for the face. He's only so big but he'll jump at you."
At morning break, as the playground rings with laughter, the unit looks like any other classroom – a safe space with art on the walls and signs of restless energy.
Without support, Peter would have been expelled. Now, with specialist staff supplementing medication, he's back in mainstream learning.
"He's bright – really bright," says his principal. "He's a lovely kid and now that he's able to get the space between getting triggered and making a decision about what he's going to do about it he's able to act pretty much normally."
The school has excellent links with social services; the wider staff is onboard; the principal fields queries from other schools; Peter's not the only child who's returned from the unit to a mainstream classroom.
But with budget pressure, there's no certainty the unit will survive.
"It's good to know there's hope for these kids," says the principal.
"We're going to be in deep shit if we don't get funding."
Rachael Wild is a mother of three who used meth while pregnant with her two younger girls. More than three years clean, she's frank about her past, explaining that she graduated from alcohol to drugs to numb the pain of a childhood blighted by sexual abuse.
"I know there will be people that will be like, 'that disgusting piece of shit woman does not deserve to have kids'," says the 33-year-old from Papamoa. "No one can beat me up more than I've beaten myself up over the years.
"Unless you have used yourself you will never understand the grip that addiction has over you. My body needed it.
"I love my girls with all my heart and I can't take back any of the past, I cannot take back the using while they were in my puku, I can't take back the using, the violence and the abuse they saw when they were first born.
"What I can do today is give them a good life, what I can do today is be that role model they always deserved but never got.
"My children need to know what this stuff does because I pray they don't go down the same road that I do.
"If they do, they have a mother that's clean, that knows what they might be going through and will be there to support them."
In Kawerau, Wild's close friend Darnell Rumbal is another recovering addict, another victim of significant childhood trauma, who used while pregnant with her youngest child.
"We've had issues at kindy with his behaviour," says the 36-year-old. "I've been honest with the kindy and they are grateful for that because they are seeing it in a lot more kids these days.
"It must be really frustrating for them to be in their own little heads not understanding why they are reacting to things the way they do.
"The issues he has, my others don't. That's how I know that's come from my addiction. But I can't change that. All I can do now is help him through it and be a better parent today."
Anecdotally, the number of meth-exposed children across New Zealand is growing.
It has to be anecdotal. There's no hard evidence, in part because users fear the repercussions of admitting drug use, like losing their kids or being locked up.
"We've got very little knowledge around the impact on our children but we do see a growing number of students who are impacted," says Lynda Stuart, president of New Zealand's largest education union, NZEI.
Schools and early childhood centres need more specialists, Stuart says. To manage meth-exposed kids and help them learn how to handle their behaviour themselves.
"Autism, ADHD, all of these different challenges are unique, but we probably know more about them so are better equipped to support children and their families. We just don't have that depth of knowledge around methamphetamine."
Wouldes has done 68 presentations about her research to doctors, police, social workers, special educators and more.
"We don't have any concrete evidence of the number of women who are using meth," she says, "but there are obviously a lot because all these organisations are desperate for information about what to do with these children."
The Ministry of Education acknowledges frontline staff see the drug's impact and says government agencies, schools, whānau and communities need to work together to tackle it.
Deputy secretary of sector enablement and support, Katrina Casey, says changes to the way support is delivered will begin being rolled out in January.
That's when the first group of learning support coordinators will start. They will lead school- and kura-wide engagement, and give parents, educators and other specialists the chance to identify barriers to learning and to allocate resources together.
"Over time, parents and whānau can expect their children's learning needs to be responded to earlier and to have easier access to a more flexible range of supports that will support their children to progress in their learning and achieve their goals."
Of course, prevention is always better than cure.
An academic article co-written by Wouldes notes World Health Organisation recommendations that past and present drug use be asked about at every antenatal visit. And that pregnant women be advised of the risks drugs pose to them and their babies.
The Herald sent a detailed request for comment to the Ministry of Health, which included questions about the way midwives and other agencies flag concerns about meth use by clients. The request was acknowledged but no response was received before deadline.
Meth is easily the most popular drug consumed in New Zealand, with an estimated $500 million spent on it each year. There are no signs that's going to change.
But we don't know exactly how children are affected and the only scientifically rigorous attempt to find out is under threat.
Wouldes needs funding for the next phase of her research. She wants to investigate how meth exposure affects the ability of children aged 9-13 to make decisions that inhibit bad behaviour.
Based on previous rejections, she's not confident.
"If we don't get funding we're probably dead in the water."
Sonia wants hard-hitting education about the perils of meth in schools and more teacher aides, like the one her grandson "adores".
She's lost hope her daughter will clean up and is focused on giving her grandchildren the best chance of avoiding the same fate.
"I know how to do the best job you can with them, but they make the decisions whether they're going to go to a party and pick up that joint or that needle and all your good work goes to shit.
"That's what happened with my daughter. I did a good job raising her. When she first went off the rails I really came down hard on myself. It took me years to realise that it wasn't my fault. And now that I'm bringing these kids up, doing it again, I put in all the hard work. I want to bring them up to be straight and not take drugs, but you just never know."