A group of teens in Ocean Reef created a Youtube video called '3L Rainbow Milk Challenge'. Vicky, who did not want her last name published, works in a hospital and was shocked to learn her son had witnessed a group of mates taking part in the craze a couple of weeks ago. Her son goes to a private Catholic school but also knew of some students attending the local high school in the Redcliffe area who were also putting themselves through the impossible challenge, she said. "What happened was my son came home after hanging out with his friends – it was a Saturday- and said 'oh mum, it was the funniest thing...' he wasn't trying to hide it from me, he thought it was a huge fad that everyone was doing and he said 'it was so funny, he drank some milk and they filmed him and put him on Facebook'," she said. Vicky said that she explained to him that it had health implications similar to bulimia where the constant vomiting damaged the stomach lining and could result in a tear or ulceration.

After drinking the coloured milk, the 'aim of the game' is to vomit it all up again. She said he also did not realise that just watching someone vomit made other people gag, which also brought up acids up from the stomach. She said as a consequence of telling him about the health implications he did not participate in the milk activities when he went out with his friends the following weekend. "Last Saturday he went out with his friends and they were doing this and he thought about it and felt sick watching it," she said. She said the teenagers were indulging their milk fascination in public areas like parks and shopping centres.

A caller to 6PR, Bev, said her 14-year-old granddaughter was also aware of the Facebook phenomenon. "She said a lot of them can't do it but they go down to a two litre and they have got a stomach of 'gold'," she said. A nine-boy group, who appear to be in their early teens, have posted on YouTube their video of trying to complete the Rainbow Milk Challenge "on a boring Sunday in Ocean Reef" dated February 12 of this year. The boys had a selection of flavoured milks and plain milk, which they dyed blue and green and drank before regurgitating it on a public oval. It is understood the human stomach can't actually hold three litres of milk which is the cause of the vomiting.

There are numerous "milk challenge" groups and pages on Facebook, which spans the United States as well. John Gardiner, senior lecturer in child psychology at Murdoch University, said it was a pretty unsophisticated practice that held no immediate threat except if they were to consume more dangerous liquids like alcohol. "Unfortunately young males compete for peer status and these things get escalated to establish status in their peer group and they become more vulnerable to attempting more dangerous things," he said. He said this "risk taking" culture was often spurred on by those in particularly competitive groups, like those on the sporting fields, but generally young males grew out of this. "These things do tend to fade out over time," he said. "But the danger of social media sites like your Facebook or YouTube, you're not competing within a small number in your peer group, you're now competing on the internet all around the world."

He said it was the desire to establish themselves as "king of the hill" through daring feats that had the potential to escalate quite quickly, which is what happened with planking and the subsequent deaths. He said Jackass provided unfortunate role models that encouraged risk-taking behaviour because they were in their 20s and could drive cars but instead choose to ride skateboards. He said while the group of nine boys, who have a name that has been withheld by this publication, featured in the YouTube video may be trying to establish themselves as a heterosexual crew they were unlikely to attract much female attention with the bad breath caused by vomited milk. Another phenomenon Vicky spoke of was "uni-coning" where teenagers go to McDonald's and order soft-serve cones and then plant them on their foreheads. She said she had also seen a YouTube film about "coning" in which a boy ordered an ice-cream at a drive-through, took hold of the ice-cream portion, then began eating the cone and filmed people's reactions.

"They all come from about year 9, 14-year-olds who become fixated on 'what shall we do next'," she said. Follow WAtoday on Twitter @WAtoday