Aria and Gianna Husrefovic each smile sweetly and give a little wave from their seats on the floor inside Melissa Wahl’s kindergarten classroom at McClellan Elementary.

It’s hard to tell the difference between the identical twins, whose outfits match perfectly down to the bows in their hair and scrunchies on their wrists.

In the same class, Heath Fetzko answers a question about the weather and talks about becoming a wrestler, while his fraternal twin, Madison, talks about the gymnastics class she can’t wait to start that day.

“I like being a twin, because my sister always has my back and because I love her,” said Heath, 5.

At McClellan Elementary, there are so many twins in kindergarten — nine sets in all — that they could fill an entire classroom all on their own. Each of the six kindergarten classes at the school has at least one set of twins and many of them have multiple sets.

“We’ve never seen anything like this before, this amount of twins,” said Wahl, kindergarten coordinator at the school.

West Jefferson Hills School District leaders say several years ago there were roughly six sets of twins in the graduating class at Thomas Jefferson High School. But they’ve never — at least as far back as they can remember — seen this many twins in one grade level at the same elementary school.

“It’s definitely a unique situation that we’re in,” Principal Justin Liberatore said.

During kindergarten enrollment this year, school leaders were surprised to see four sets of twins lined up to start school at McClellan this fall. Then, they just kept on coming.

The last set of twins enrolled in kindergarten the second week of school.

“I was like, ‘Everybody gets a set of twins this year!” Liberatore said he told the kindergarten staff. “Almost everybody’s going to have two sets of twins!”

Parents have the option to choose if they want to keep their kids together. All nine parents chose to keep their twins in the same class this year, Liberatore said.

One person recommended experimenting and putting all of the twins in one class, Liberatore said. That didn’t happen.

Teachers say each set of twins is different.

“They’re very hands-on with each other,” said kindergarten teacher Ashley Lloyd.

While some of the twins do everything with their siblings, others like to separate and do things on their own.

“It’s both. They hang out with each other and then they go with different groups,” Lloyd said.

Aria and Gianna, 6, like to do things together.

“It’s fun being sisters. We have someone to play with every day,” Gianna said.

There are days where it takes a minute for their teacher to tell them apart.

Every day, the girls wear matching outfits. To start the year, their earrings were different, so Wahl could tell them apart. But once she let on how she was differentiating between them, the next day — and ever since — they’ve come in with matching earrings to complete the outfit.

One day, Aria couldn’t come to school with her sister because she was sick. That made them both sad, they said.

They like to take care of each other. Aria gets Gianna tissues when she has a nose bleed and Gianna wakes up Aria each morning so they can get to school on time.

“My sister never leaves my back when I’m scared,” Aria said. “That’s why I like being twins, because I love my sister and she likes me too.”

They do have a little secret way for people to tell them apart: Gianna has a small freckle on her neck and braces on her back teeth.

Heath said he likes having so many twins in his grade. While his sister has his back, so do all of the other twins, he said.

McClellan’s nine sets of twins say there’s a lot to love about having a sibling their own age. They sometimes share a room, they get to share a cake on their birthday and they look out for each other.

“You get to play toys with them and sometimes they’ll even let you have their toy and share it,” said MJ Suckfiel, 5, who wore a matching “Jaguars” T-shirt with his sister Evie.

Silas Finocchi ran over and hugged his sister, Sutton, in the middle of class. Sutton later gave her brother a squeeze as they walked down the hallway together.

Chloe Kuftic, 5, said she likes having a twin brother, Caelan.

“They kind of take care of you, if you’re sick or alone,” she said. “Or you can play with them and you share toys and stuff. We can wrestle, too. And we can play with each other and we care about each other.”