Terra Bella is home to several sets of twins

TERRA BELLA, Calif. (KFSN) -- At recess in Terra Bella, four square rules. It's a simple game, but there's nothing simple about the players.

"People get confused a lot," Brandon Torres said as he stood next to his brother, Brayan.

In fact, people get so confused, "last year, they stopped making us wear the same clothes," Brandon Torres said.

It's only fair, right? But it's not just these twins that are confusing people. There are 11 sets of twins, and that's just at Terra Bella Elementary.

"I have to go by where they sit, and I watch where they go," Terra Bella Elementary teacher Amy Walker Zedda said.

You'll find two more sets at the middle school -- even future Tigers in training running around campus.

"I never noticed it until today. I mean I had seen maybe one or two, but I never noticed there were so many," said Brenda Madrigal, Aliyah and Alexander's mother.

So what's behind all these twins in Terra Bella? Dr. Sanmaan Basraon specializes in maternal fetal medicine at Valley Children's Hospital. She says the answer is complicated.

"The rate of twinning is a complex trait and has genetic and environmental factors attached to it," said Basraon.

There are two types of twins: identical, when an embryo splits in two, and fraternal, when two separate embryos grow in a mother's womb. Fraternal twins are more common than identical twins. Fertility treatments can increase the odds of having fraternal twins. But parents here say all of these twins were conceived naturally.

"My sister says it's the water. I don't know," said Madrigal.

It's a theory that Basraon says doesn't add up. But another study published by the Oxford University Press says mothers who've had twins before are four times more likely to have twins again -- like Jewelyssah and Alyssah's family.

"My sister had two sets of twins," said Maria Trujillo, Jewelyssah and Alyssah's grandmother.

In other cases, fraternal twinning can run in the family, like Alexander and Aliyah's mom.

"My family and my husband's family, and then my dad was a twin," said Madrigal.

Surprisingly, the chances of having fraternal twins also increases if you're overweight or extra tall. Older women are also four times as likely to have fraternal twins than younger mothers. But most of these twins in Terra Bella are identical. Basraon says this is an unusual case, and more research is needed in the field of twins.

"There were none in my elementary school," said Basraon.

All statistics aside, for Adiline and Marlene Leon it's nice not feeling so alone in their togetherness.

"There's like a whole class of twins, so I'm more comfortable with that now," Adiline Leon said.

Which is good because the duplicates don't stop with this generation.

"Supposedly there's even more coming down the line. There's a momma that's gonna have another set of twins who already has a set," said Zedda.

Which means confusion on the four square court is here to stay.