When Matt Hyatt began playing football in fourth grade, he thought he would be the only one in his family on the field.
His twin sister, Nicole, had other ideas.
"I really loved playing football," Matt said.
"And I didn't like that he thought he could play a sport without my being there," Nicole added.
The 13-year-olds are now seventh-graders at Carson Middle School in the North Allegheny School District.
Both are on the school's seventh-grade football team.
"It is very unusual," said Bill Burns, Carson's head football coach.
He has coached girls before, but the Hyatts are his first set of twins.
"It has been a pleasure," he said. "Both of them are great kids. They work hard. She definitely ... wants to mix it up with the boys."
The twins' mother, Kim Hyatt, said Nicole started swimming at age 5 and won several swimming and track championships in Butte, Mont., where the family used to live. The father of one of her teammates coached football, and Matt signed up.
The coach told Nicole and her friend they couldn't play football.
"That was the wrong thing to say to my daughter," Mrs. Hyatt said. "I don't care what she has to do to prove you wrong."
So Nicole and her friend began playing football. Nicole scored a few touchdowns and got a lot of playing time, her mom said.
The family, including 15-year-old R.J., moved to McCandless last year.
Matt said a lot more girls play football in Montana than they do here.
Nicole, who plays running back and receiver, said the boys on the team didn't know what to make of her at first. "Then they got nicer," she said.
"They saw that she could make plays, which she does -- a lot," added Matt, who plays lineman. He described his sister as "nimble."
North Allegheny has procedures to follow in sports involving both genders, Mr. Burns said. It involves holding meetings in neutral locations, rather than the locker room; making sure the equipment fits each player properly; and ensuring that facilities are adequate at away games.
"You have to be aware of what's being said," Mr. Burns said. "You have to make sure that the boys treat her with respect and dignity."
The twins' mother said the two are "polar opposites" in personality.
"Football is their one common ground," she said.
Mrs. Hyatt said that, although she supports Nicole 100 percent, she worries about injuries because her daughter is smaller than many of the boys playing football.
"At seventh- and eighth-grades, your bones are still growing. You can get an injury that can last you the rest of your life," she said.
Nicole acknowledged that she may stop playing after this year because "the guys are getting too big."
Matt, however, told her that she should play in eighth grade and then stop.
"She has played with me for the last three years," he said. "You get used to it."
Sandy Trozzo, freelance writer: email@example.com.