Where have all the street children gone? That is a question asked by many Johannesburg residents in recent months.
People pointed out that street children had seemingly "disappeared" and some even suggested that they had been "cleaned off" the streets and spirited away to secret institutions or camps, in a mock dress rehearsal for the expected influx of visitors for the 2010 soccer World Cup.
But a search this week for the "missing" children, by a team from The Sunday Independent, revealed that the "problem" of street children is only a sliver of a much larger and more daunting problem for the city authorities.
Johannesburg's street children have merely shifted from their usual haunts to be closer to shelters in Hillbrow, Berea and End Street, where there is warmth and food.
Or they have moved to areas, such as Bruma and Joubert Park, where the residents are less likely to call the police.
We spent time this week with Michael Mudau, who some teenagers, and even some adults, might think that has got it made.
The diminutive Mudau doesn't have to wake at a specific time to be punctual for work. He doesn't have to wash or pay rent. He doesn't have a nagging family. No one tells him what to wear or eat or that he must swallow vitamin tablets.
But that's about as good as it gets.
The only meal of which Mudau can be certain is the one served at midday at Hillbrow's Twilight Children shelter.
The only dietary supplements he knows of are tik (crystal methamphetamine), thai white (a cheap heroin derivative, often cut with rat poison) or, best and cheapest of all, good old glue, which on the coldest nights apparently makes one "feel warm inside".
Mudau does have a family of sorts - a pack of buddies with whom he hangs out on the streets of Hillbrow.
So, when he beds down in a flat without water in Quartz street and in the clothes he has worn all day, he generally does so with a familiar group of people.
But a couple of weeks ago one member of the family grew annoyed with another over R5 and cut the latter's throat, and then stabbed him 16 times for good measure.
During one early evening we spent with Mudau in Hillbrow, a taxi driver was shot dead in his vehicle near the constitutional court precinct. No one in the thronged streets seemed to notice or care.
A few minutes later we spotted a man sprinting down the street clutching a handbag that he had apparently snatched.
A good night's sleep is also hard to come by.
Three different groups of street children - one from Hillbrow, the second from the Joubert Park area, and another group of girls from End Street - said that Metro police habitually set their blankets on fire, apparently as a means of forcing them off the streets and into shelters.
"Sometimes the policemen laugh; they think it's a big joke," said one boy.
Social workers, outreach workers and staff at the shelters do not doubt such stories.
Mildred Mhlanga, of Johannesburg Child Welfare's Thembalethu Project, said that a number of girls from the project had watched as Metro police lifted their blankets from the rubbish bins where they were stored and set them alight.
When these allegations were put to him, chief superintendent Wayne Minnaar, the spokesperson for the Johannesburg Metropolitan police department, said angrily: "I deny that our officers would do such a thing. I deny it not only categorically but emphatically."
Besides troubles with the police, Mudau and his friends do not seem to be loved by many residents of Hillbrow.
"They beat us for stealing," said Mudau, "but it's not us, it's the older boys who do that."
Asked what he meant by older boys - he is 21 - Mudau replied: "I mean the bigger ones, the ones of 26 or 27."
Mudau's description of himself as "a child" is more shrewd than confused.
If it was known that he is over 18, he would, strictly speaking, be denied food at the Hillbrow shelter where he eats.
Wandile Zwane of Johannesburg's social development department said: "There has not been a clean-up (of street children) or anything like that. But we have been going out on the street in task teams to find out what is happening.
"And we are focusing more sharply on the homeless that live on Johannesburg streets because the problem has changed enormously during the last five years and it is quite serious."
He said that outreach teams had found three worrying developments with regard to the people living on Johannesburg's streets.
First, the average age of people on the street had risen to comprise mainly young adults. Second, the numbers of females "on the street" had risen radically. Third, many homeless people were migrants.
"Once the children are over 18 they are no longer children," Zwane explained. "They're young adults for whom we have to organise different programmes.
"The presence of girls and women changes the dynamics of everything. There are issues of prostitution and vulnerability.
"And then there are many migrants, foreigners, out there. What do we do with them?"
Duduzile Mabizela, a trained nurse who works as an outreach worker at Twilight Children, confirmed that she had seen the ratio of males to females living on the street change from 90:10 to 50:50 over the past two years.
George Dalka, who works at the New Creation programme for street children, said that it was clear that the huge increase in the numbers of parentless households in rural areas, because of Aids, was bringing young people into the city in droves.
This phenomenon was almost crippling the provincial and city programmes aimed at moving street children into foster care, "new" families or shelters.
"What this means," said Zwane, "is that we're not fussing about 2010, or about getting rid of street children, or that kind of stuff.
"What we're concerned with is dealing with the new kind of homeless problem that we are facing."
Meanwhile, this week, as Youth Day loomed, Mudau and his friends were guiding cars into parking in Hillbrow, offering to wash them, jeering at a passing Metro police vehicle and huddling for warmth around a fire that they had made in the middle of the pavement.