However, there are still a lot of mysteries in the world with no scientific explanation for them. One such puzzle is the curious case of a large number of multiple births in Kodinhi, a small village in the state of Kerala.

The quaint and remote village of Kodinhi lies in the Malappuram district of Kerala and houses about 2000 families. From the first glance, it looks like any other village of the southern state. But when you take a closer look, you find twins, both identical and fraternal, at every nook and corner.

The village has over 250 pairs of twins with an average of around 45 twins per 1000 births, a number which is too high when compared with the national average of less than 9 and a global average of about 13 twins per 1000 births.

According to locals, this bizarre phenomenon started about 70 years back and now even the girls who get married outside the village exhibit a substantially high rate of having twins.

Kodinhi has now gained international recognition and is aptly nicknamed as ‘Twin Town’. Also, the village has started a ‘Twins and Kin Association’, the first of its kind in the country.

A lot of scientists have studied the soil and water of the village, some even went on to study the genetic patterns and food habits of the locals, but are yet to come up with a concrete explanation for the marvel.

Very recently, a joint team of researchers from India, Germany and the UK have started collecting saliva samples from the twins to isolate their DNA and crack the code behind this significantly high number of twin births.

According to estimates, there are at least 400 pairs of twins in the village that has a population of 2000 families. While official estimates in 2008 pegged the number of twins in the village to 280 pairs, the number has only increased in the years that followed, residents point out. While the national average of twin births is not more than 9 in 1000 births, in Kodinhi, the number is as high as 45 in 1000 births.

In October 2016, a joint team of researchers from various institutions including CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Kerala University of Fisheries and Ocean Studies (KUFOS) and University of London and Germany visited the village to find answers to this phenomenon.

The researchers collected saliva and hair samples from the twins to study their DNA. The study is simultaneously being conducted in Kodinhi, Hung loc commune in Hung Hiepfrom South Vietnam, Igbo-Ora in Nigeria and Cándido Godói in Brazil, where the number of twin births is high.

Prof E Preetham of KUFOS points out that though there are multiple speculations about why this could occur, nothing has been proved scientifically.

"While many say that it is genetic, there are also speculations that a particular element in the air or water in the village could be the cause of this phenomenon. As far as our study is concerned, we have collected the samples from people in Kodinhi and is in the process of collecting samples from the other communities too. As of now, the phenomenon is yet to get a scientific explanation," Dr Preetham said.

A blue board that reads "Welcome to the God's own Twins Village--Kodinhi”, welcomes visitors to this village. The president of Twins and Kins association, the only association of its kind in India, P Bhaskaran says that people of Kodinhi are now eager to know what causes so many twin births in their village.

Bhaskaran’s family has been a resident of the village for over two generations, and there are others who moved to the village over the past years. Irrespective of where they came from, or what religion they belong to, the strong thread that binds the people of Kodinhi is the bizarrely high number of twins, in the last three generations.

It was the curiosity of a pair of twin sisters in 2006 that led to the village taking note of the pattern of high occurrence of twin births in their village.

"At the time, this pair of twins named Sameera and Femeena were students of 8th standard in the IISC school near here. They noticed that there were eight pairs of twins in their class alone. They found that there were twins in other classes too. This was a major discovery as far as they were concerned,” Bhaskaran said.

The twin sisters, went on to conduct a mini-survey as a part of their class assignment to ascertain the number of twins in their school and they found that there were 24 pairs.

This mini-survey conducted by the two school children is what marked the beginning of Kodinhi's discovery. Soon, the news about the twin sisters' discovery spread, which led to the villagers taking stock of the pattern.

"In 2008, we formed a small committee and conducted a survey in all the houses in the village. To our surprise, we found that there were 280 pair of twins then. It was then that all of us realised that there was something special about our village. We did some research and got to know that the only other place where such a phenomenon is seen is in Brazil. We then formed the association and got it formally registered as a body that works for the welfare of the twins," Bhaskaran said.

For 41-year-old Samsad Begum, giving birth to a pair of twin girls fourteen years ago, was a source of double joy. Ishaana and Shahaana are now studying in the 9th standard but they are not identical twins like most others in the village. Samsad moved to Kodinhi after her wedding in the year 2000.

"We never gave much thought when we had twins. But then after a few years, everybody began to say that our village has the highest number of twins in the country. That's when we began to think how this was possible," Samsad said.

While Samsad's family did not have any twin births in the past five generations, that was not the case with her husband Majeed's family. Majeed's father had a twin brother and the family believes the answer lies there.

However, not all families have a history of twin births. Praseena (34) is the only daughter Sukumaran (71), a retired government employee, whose family has been living in Kodinhi since the past two generations. Their family has had no twin births but now their daughter Prasanna is a mother to a pair of twins.

"After our daughter's wedding, she moved to Qatar to live with her husband and would only visit us once a year. Ten years ago when she conceived, we didn't imagine that she would give birth to a pair of twins," Sukumaran says.

While the families have their own speculations about why the phenomenon occurs, Abhilash, an autorickshaw driver, who is father to two pairs of twins, is worried why the state government has not yet extended any sort of financial help to the families who have multiple pair of twins.