In their original villages, the young people of Darfur had many responsibilities; they cultivated the land, took care of cattle and produced charcoal, while some went to school.
In the sprawling expanse of makeshift tents that make up Kalma camp for internally displaced persons (IDPs), however, the story is different.
"Adolescents in the camp have nothing to do all day. They just sit idle," said Malik Elbadawi, a health officer for the UN Children's Fund (UNICEF) in nearby Nyala, the capital of South Darfur State.
Kalma is the largest IDP camp in Darfur, although there is no reliable estimate of its total population. According to aid workers, between 150,000 and 160,000 people live in the camp, making Kalma one of the largest concentrations of people in western Sudan's war-torn region.
"What does an adolescent with a lot of energy do when he is confined to a camp?" a child protection worker in Kalma camp asked. "His energy gets used in the wrong direction."
Young adults can be seen moving around the camp. Some have a wheelbarrow and make a little money transporting bags of millet or jerry cans of water. Some make grass mats while others sell cigarettes.
According to aid workers in Kalma, some of the young adults, especially those who have nothing to do, have got involved in petty crime and commercial sex work.
Other IDPs were however trying to discourage sex work in the camp.
"Adolescent girls are not allowed in the market anymore and neither are the soldiers, who used to be their main clients," one aid worker said.
Despite efforts to discourage sex workers, a health worker added, rape committed by other IDPs had become more common. Some of the incidents of rape could be blamed on young adults who had nothing to do, she noted.
"Because of the crowded situation in the camps, whole families share one tent so children see their parents having sex," she said. "Adolescents then start to replicate their parents' behaviour at an early age."
The UNICEF education officer in Nyala, Phuong Nguyen, said the needs of adolescents in Kalma - and in most other camps across Darfur - were not being met.
"UNICEF's emergency education programmes focus on children from seven to 13 years - [primary school] grade one to eight," she said.
In most IDP camps there were only a few students at secondary level, Nguyen explained, and secondary education was usually not seen as a priority in an emergency setting.
"In Kalma, they really need a secondary school, but there is not a single one at the moment," she added.
Ibrahim Issa Yusuf, area supervisor for child protection in Kalma for the Sudanese Popular Committee for Relief and Rehabilitation (SPCR), estimated that there were approximately 20,000 adolescents in Kalma, of whom 9,000 were attending primary school.
Nguyen estimated that there were currently 322 students in the eighth grade in Kalma, while about 160 were taking the eighth grade exam in order to continue with their secondary education.
"We do have quite a few over-age children in primary school classes," she noted.
She knew of 13-year-old girls sitting in a classroom with seven-year-olds, but said there was a limit to the extent young adults could join children's classes.
The only secondary school in the area was in Belil, a nearby settlement with a large number of IDPs who fled the war in southern Sudan. Some of them had been in the camp for over 15 years.
"This school has only been open since the beginning of July," Yusuf added. "Some adolescents from Kalma can go there, but most can't."
Adam Atom Adam, 19 years old, has been in Kalma for more than a year and is one of the lucky few who could attend Belil secondary school.
"Every morning, I leave early and walk - without breakfast - for more than an hour to go to school. I stay there until 1515 hours and then walk back; I eat after I come back," Adam said.
Adam's 16-year-old friend, Merghani Abdel Bari Mohamed, who also attends the secondary school, fears that the school fees of 15,000 Sudanese dinars [US $6] will soon drive most IDPs out of the recently opened school.
"I expect that, if not all of the IDPs will stop going to Belil, at least most of them will," Mohamed said.
Adam and Mohamed's friends did not manage to be admitted to Belil, and were staying at home.
"They just stay home; they go to the market, move around, go back to the house and then to the market again - they do nothing," Mohamed said.
Some teachers among the IDPs had started to teach some informal classes for adolescents, but students had to pay and only very few could afford it, Yusuf noted.
A group of adolescents had proposed to support the community by rebuilding the houses destroyed during the rainy season, Yusuf added, but there was no money to provide them with tools.
So-called "child-friendly" spaces where children can sing, dance, draw, and play games also cater to the needs of smaller children in particular.
"In some child-friendly spaces we have started to organise activities for older children, mostly sports, during the evening," Yusuf noted.
Hamida Abdel Shafi is 17 years old and goes to the seventh grade every day from 1500 to 1800 hours. The rest of the day, she stays at her parents' house.
"I went to a child-friendly centre to participate in the activities, but there were too many children already. I'm now on the waiting list," Hamida said.
Nguyen added that providing catch-up classes, accelerated learning and basic literacy programmes for young adults would fill a real needs gap within the camp, and UNICEF and some NGOs were discussing the issue.
Besides literacy, vocational training and life-skills lessons - on sanitation, food preservation and HIV/AIDS, for example - would also be a welcome addition to the educational services provided to young adults, she said.
With UNICEF's support, SPCR has organised some carpentry, tailoring and proposal writing training for young adults, but lacked the money and capacity to do this on a regular basis.
"Adolescents are a relatively small but very important group and if we don't do anything for them, it might become a large problem," Nguyen cautioned.
This article was produced by IRIN News while it was part of the United Nations Office for the Coordination of Humanitarian Affairs. Please send queries on copyright or liability to the UN. For more information: https://shop.un.org/rights-permissions