The four celebrated their first birthday on the same day about two months ago. Each is now about 70 cm "tall" and weighs about 15 kg, though the four weighed between 720 to 940 grams after their premature birth in August last year. And not surprisingly when one of them cries for food, the others follow almost immediately. Meet the four surviving quintuplets born to a migrant couple in Guangzhou, Guangdong province, who have, thanks to their parents, grandparents, relatives and countless well-wishers, survived many medical complications and fought through their family's financial constraints.
The two boys and two girls have received widespread public attention, and not just because they are the first quintuplets - the fifth, a boy, died of cerebral hemorrhage four days after birth - to be born in Guangzhou, but also because their parents are poor migrant workers from Henan province and needed financial and other help to bring them up.
But is their growth normal? Are they as healthy as other children of their age?
"Their general growth meets the average level. The oldest seems the healthiest. We can't expect a lot from children born premature," says Wu Jieling, director of the child healthcare department of Guangdong Provincial Maternal and Child Care Hospital.
"The oldest one is learning some 'social communication skills' , as was as evident when he was playing the pampered child with his grandfather," Wu says. In fact, all four can say mama and papa. "Despite still being on all fours, the second and third babies move quite fast. The youngest is healthy, too, but has a hearing problem, and needs further check-up."
Bringing up the four babies has by no means been easy for their parents and two grandparents, though some relatives have helped by babysitting.
"We wash their feeding bottles three times a day," says Zhang Xiao'an, 49, paternal grandfather, who is now a skilled formula milk maker. The milk must be prepared fast, because when one cries for food, the others soon follow.
How much milk do they drink each day? Grandpa says they need one and half 450-ml cans of formula milk powder a day, though they also eat noodles and steamed buns.
Zhang gave up work as a waste collector - he used to sell waste materials to recycling plants to earn a living - when the babies were brought home in December last year after being in hospital for more than four months.
Zhang is the first to get up in the morning and the first thing he does is to wash the clothes of the little ones.
Coordination is needed, he says, when the four fight for the feeding bottle or when they cry in a chorus. "As they grow older, they move faster ... and it is becoming more difficult for me to control them."
Grandpa says that he wants to teach them more words - apart from mama and papa - but he does not have enough time to do so. You can see why. At home in the summer heat of September, the half-naked babies are having a roaring time in their 50-square-meter home in what can be called a semi-rural area of Huangpu district, and Zhang was having a tough time keeping pace with them and wiping the floor with a towel whenever they peed.
Zheng Xiaoni, the 24-year-old mother of the four, is a lot more at ease today but she still gets the jitters whenever they fall sick, which they have several times after being discharged from hospital in December.
One night two and half months after returning from hospital, the second child had fever. "When we took it to the hospital", the doctors diagnosed it as "pneumonia and soon the other three" also had a temperature. Zheng says. Since they were born premature, they are more susceptible to infections than normal babies.
Doctors have advised the mother to improve the ventilation and sanitation in the house and change the babies' clothes according to the change in temperature. But good ventilation and sanitation are difficult to come by in their home - a rented apartment in a narrow alley. The walls around the staircase leading up to the two-bedroom apartment shared by the family of eight is damp.
The family cannot afford more than a worn-out sofa and other overused furniture, some of which were retrieved from the dumping ground. The smell and smoke of burning coal is strong in the neighborhood.
Even personal hygiene comes at a premium. The four babies are bathed in a baby bathtub in turns. But the water is not changed for the second, third or fourth baby, and the two girls always follow their brothers. Despite al the odds, the babies are battling on, and successfully.
So how has the family managed to fight it out for more than a year? The family depend on the 3,000 yuan (S$586.3) a month that the babies' father Zhang Zhongtang earns as head of a convenience store, a job he was offered after the quintuplets' story became public.
After work, he ferries passengers on a motor-driven tricycle, even though it is illegal, to make some extra money to make things better for the family. To save money, the adult family members eat as little meat as possible, the grandpa says.
The family received more than 1.19 million yuan in donations for the treatment of the children, from which it donated back the unused amount of about 380,000 yuan to a programme that helps children of low-income families. The charity group, which collected and managed the donations, has also raised 210,000 yuan for the children's education and covers their medical expenses. Besides, the family has been receiving formula milk power and diapers free from manufacturers, and clothes, toys and electric fans as gifts from local people.
Zheng now wants to find a job with flexible working hours, preferring to work from home, to lend her husband a helping hand, but that is easier said than done.
Nevertheless, despite the hardships, Zheng is happy to see her babies grow. "I was happy when they had their first tooth ... and it is so wonderful to see them laugh," she says, hoping her babies will be "healthy and receive good education".