When Niu Jian Fang and Jiao Na got married they knew China's rules - one couple, one child.
By James Reynolds
BBC News, Henan Province, central China
A woman can only give birth once.
So, four years ago, Jiao Na got pregnant and gave birth to a son, Bei Bei.
And then a few minutes later she had a daughter, Jin Jin, then another son Huan Huan, a second daughter, Ying Ying, and finally another girl, Ni Ni.
She and her husband beat China's one-child policy by having quintuplets.
But life has not been easy for them.
Their small farm does not bring in much money.
They have had to give Ying Ying to a relative because they cannot afford to raise all five children on their own.
Still, they managed to beat China's system. But they are reluctant to explain how they did it.
"What's your secret?" I ask them.
Niu Jian Fang stares ahead. Jiao Na laughs nervously.
Buffalo village has an above average number of twins
"Difficult to say," she answers.
No-one here in Buffalo village wants to say it openly, but privately families admit they use fertility drugs to get round the one-child limit.
One woman says her parents-in-law put the drugs into her food to make sure she would conceive twins.
This is a farming village - families need more than one child to help till the land.
Because of the fertility drugs, this village has more twins on one single street than you would expect to find in the entire village.
Just down the road from the quintuplets' house, there is Lou Yuan Mei and her two-year-old twins, Lin Kai and Lin Da, dressed in identical orange jumpsuits.
A few doors down, Wu Xiaofang is happy to pick up and show off her baby twins, Jiao Jiao and Fei Fan.
Near the village, the records of the county maternity hospital are filled with lists of multiple pregnancies.
Dr Guo Gui Fen turns the handwritten pages slowly and points to the name of each mother who conceived twins or even triplets.
"We've seen a huge rise in the number of twins in recent years," she says.
"That's all because of the fertility drugs that are easily available."
Just across the road from the hospital, there is a chemist which sells drugs to Buffalo village and to other nearby villages.
I head into the shop to test how easy it is to buy the tablets without a prescription.
"One box?" asks the shop assistant.
"Just one," I reply.
She asks no more questions and heads off to get the last remaining box of Clomifene Citrate Capsules, which costs just 7.5 RMB ($1).
The assistant takes the money and hands me the box of tablets. It is that simple to get hold of fertility drugs in this part of China.
China introduced its one-child policy in 1980 because it was worried about its ability to feed a growing population.
In modern China, more and more people object to the state telling them what to do
In towns and cities, the policy is often strictly enforced.
Some women are sterilised after they give birth to their first child.
Others have been forced to have abortions if they get pregnant for a second time.
Couples face heavy fines if they go ahead and have a second child.
There are some exemptions, however, with families from ethnic minorities allowed more than one child.
Some rural families are also permitted to try for a son if their first child is a daughter.
But those Chinese who are limited to just one child increasingly resent the policy.
In modern China, more and more people object to the state telling them what to do.
On 19 May, the residents of Bobai, a town in China's southern Guanxi Province, rose up against the policy.
China's government strictly enforces its one-child policies
Communist Party officials started going house to house to collect fines for having a second child.
According to reports, the officials tried to intimidate rule-breakers into paying, but locals fought back by burning cars and destroying official buildings.
Many Chinese would prefer to avoid this kind of confrontation with the state, which is still hugely powerful.
That is why so many choose to take fertility drugs in the hope of a multiple pregnancy.
If you have all your children in one go in China, you do not have to worry about a fine and a fight with the Communist Party.
The Chinese government insists its one-child policy has to remain in place for many more years, as it believes it is the only viable way of controlling the country's population.
But with fertility drugs, the people of Buffalo village have now found their own reliable way of beating the system.