City dwellers can spot the young maids fresh from Chadian villages from afar - by their ragged dusty clothes and unsophisticated hair, and the way they shy away from cars speeding up and down the streets.
Teenagers from far-off rural villages are flocking increasingly to the capital N'djamena to become domestic workers, one of the most elusive forms of child labour as it takes place behind the closed doors of private homes.
"They're aged between 8 and 15, and earn very little," Felicien Ntakiyimana, who works on child protection for the UN Children's Fund (UNICEF) in Chad, told IRIN.
In the dim early hours, the teenage girls walk in clusters of 10 to 20 along the big central thoroughfares of N'djamena, the Avenue Charles de Gaulle and Avenue Mobutu, on their way to work, often 8 to 10 km from the place where they sleep.
Chadians call them "bey", a corruption of the old colonial word "boy," used for the man servants who catered to their masters' every whim.
In the vast central African desert nation of more than eight million people, the young girls who come up from the countryside in search of jobs are mostly aged between 12 and 15 and are easy prey for ruthless employers.
"The conditions are very tough, they're worked around the clock and exposed to violence," Ntakiyimana added.
Marcelline Dande, 13, the only girl in a family of nine children, said she came up to N'djamena from the village of Peni in southern Chad in January 2004 in the hope of staying with an aunt.
But after a week the aunt sent her back to her home in the largely Christian and animist south, where modern ways are increasingly coming into conflict with conservative values. It made the aunt angry to see a young girl off on her own in the city, especially since she was her parents' only daughter.
Marcelline ran away however and refused to go home. "I joined up with a group of girls from Man-Gueri, a village not far from Peni. They helped me find a job with a Muslim trader," she said. "I haven't seen my aunt since."
Marcelline and the seven other girls she lives with get up every morning as soon as the rooster crows at around 4 a.m. They splash a little water over their faces to wake up before heading off for work.
They share a small room about three metres by two and sleep on mats on the floor. For this humble abode they club together to pay a monthly rent of 3,000 CFA francs (US $6).
They don't eat breakfast. Their one meal a day comes at around three o'clock in the afternoon at work - a bowl of rice or millet cakes.
"I wash the dishes, do the laundry, clean the rooms, sweep the yard, bathe the children, fix breakfast, lunch, tea and dinner. I finish around five or six in the afternoon and get home around eight p.m. very tired," Marcelline said.
Such slavery-like conditions have been repeatedly decried by organisations such as UNICEF and the International Labour Organisation (ILO).
The ILO reckons that nearly one third of the 48 million children aged under 14 in sub-Saharan African are put to work as child labourers.
So why did Marcelline and the others leave the village?
Working to prepare for marriage
"All the girls my age want to come to the city to buy the things they'll need when they're married," she said.
"It's become a shame to stay behind in the village until the day you marry. And here you learn to speak Arabic, which is a foreign tongue in our villages," where people speak Sara.
In the big city the girls can find new modern clothes in cotton and natural fabrics instead of the old nylons and synthetics found in the rural hinterland. And there are shoes and aluminium cooking pans, headscarves, earrings and "djalay djalay" waist-beads worn to seduce husbands.
Sarah Kondede, aged 15, is already married, but she left her husband behind in the village of Dononmanga so she could work for a brief spell in the capital to earn a bit of money. She lives in the suburb of Boutha Al Bagaar, far away from the city centre where she said she worked for a butcher called Khalil Djallabi.
Her work consists of washing the dishes, sweeping the yard, cutting the wood, making tea and soup, doing the shopping and taking the children to school. "I never stop," she said. "As soon as the boss's wife sees I've finished doing something, she gives me something else to do.
"If it takes too long she insults me and calls me "abit", "noubay" or "sakhrani" (which mean slave, dirty slave or drunk in the local dialect of Arabic).
Although a maid's workload and schedule may be more or less identical from one employer to the next, the pay varies, as do the conditions.
Sexual harassment is one problem, said Juliette Tore.
"One day, after three months of work without being paid a cent, I was washing the bedroom floor when the master came in from behind, looked at me and touched my bottom. He asked if his wife was about to come home and I said I didn't know."
"This all happened two days before the end of the month. He grabbed me and pushed me onto the bed. I fought and one of my fingers touched his eye. He twisted my arm, hit me and chased me out the house without paying my wages," said the teenager, who comes from the village of Bekessi.
Earning a pittance
Other girls, most of whom don't know how to read and write, are accused of theft or of trying to poison their employers, and are sacked.
"But they're all lies," said Kondede. "All they want to do is send us off without pay."
Their wages are among the lowest in Chad, the world's 11th poorest nation, where two out of three citizens live below the poverty line, according to the 2004 UN Human Development Index.
Ntakiyimana said monthly pay averages between 5,000 to 15,000 CFA francs (US $10 to $30), but when the cost of broken glasses or plates, or fines for being late, are subtracted from the total "sometimes you only earn 6,000 or 7,000 CFA francs", said Kondede.
One employer of a teenage maid brushed off all criticism, saying the girls were being done a favour by working in big N'djamena homes.
"If people don't discuss the offer you make, what're you supposed to do as an employer?' said Younous Abba, who lives on 40 Metre Street, which is home to many Arab traders.
"They don't even know how to clean or prepare clothes. They're peasants. We are giving them help," he added.
But one of the leaders of the Chad domestic workers' association said the labour authorities were at fault for failing to control wages and labour contracts.
"The authorities don't check on the domestic workers," said Kaguere Hamit.
"Nothing is inspected in this country, including work contracts. The minimum wage is 28,500 CFA francs (US $57) a month, so how can people hire workers for 10,000 or 15,000? ($20 to $30)"
The Chad government has signed up to the ILO child labour convention which aims to prevent the exploitation of children. Officials said an inter-ministerial committee currently was currently working on a text to tackle the problem of child domestic workers.
The lure of money in the big city exposes many of the youngsters to sexually transmitted diseases.
"Many people believe the girls are still healthy because they're 'ja min khadi' (which means literally 'straight from the village'), meaning that condoms aren't required," said journalist Diponbe Payebe of the weekly Le Temps.
And more and more often, at food and drink stalls across the capital, men come looking for a "ja min khadi'.
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