Teachers at Creek View Elementary School in Alabaster must have wondered if they were having vision problems when school started about a month ago.

They saw pair after pair of children, dressed alike, many of them holding hands as they walked down the hallway to their classrooms.

They were seeing double, but they weren't hallucinating. With the school's newest kindergarten class, a whopping 17 sets of twins are on the rolls. Kindergarten has the most with nine sets; first and third grades have two sets each; and one set is in second grade, according to Joyce Dixon, Creek View principal. Three more sets are in higher grades, Dixon said.

This is not a record, however. According to the website Twinstuff.com, a school in Great Britain reported 20 sets of twins in 2007, and several schools in the United States and Britain have reported 19 sets of twins enrolled.

Amber Wood, a kindergarten teacher at Creek View, said her first experience with twins in the classroom occurred about four years ago. Since then she has taught a set of boy-girl twins and a set of twin girls. This year she has a set of boys and a girl whose twin is in another class. Wood said she enjoys the time she has with twins. She says they are not hard to distinguish because she gets to know each child as an individual.

Kelly Preveaux said she and her husband, Neal, were not surprised when they learned their family would double with the birth of Maddie and Conyers, who are among the twins in kindergarten at Creek View.

"My father is a twin, and my maternal grandmother is a twin," Preveaux said.

Lori Stovall and her husband, Keith, were stunned because no one had any suspicions until an ultrasound five months into her pregnancy. Hannah and Haley, both girls, are fraternal twins, but their heartbeats were perfectly aligned and sounded like a single heart when listened to through a stethoscope.

Pamela Smith and her husband, Jerry, didn't think their new addition would be two.

Breanna and Savanna Smith are identical twins, but Breanna is a couple pounds heavier than Savanna. It's one of the few ways to tell them apart. Smith said both girls have seven letters in their names, and "'B' in 'Breanna' means biggest, and 'S' in 'Savanna' means smallest."

Twins sometimes are the result of a treatment for infertility, but most of the mothers of the twins at Creek View said their children were conceived the traditional way; no in vitro fertilization was involved.

The Centers for Disease Control reported 32.2 twins born per 1,000 births in the United States in 2005, the last year available. In 2008, the Alabama Department of Public Health reported 1,027.5 sets of twins born out of 64,345 total births in the state.

Fraternal twins can be boy/boy, girl/girl or girl/boy. The babies develop from two separate eggs, hence the difference in gender and appearance. Identical twins develop from a single egg; that's why they're the same gender and look almost exactly alike.

With so many twins around, the Birmingham Area Mothers of Multiples is bound to be represented -- and it is. Tonya Nealon is president of the group, and she and her husband, Jamy Ard, have fraternal twins Tristen, a boy, and Tyler, a girl, in first grade at Creek View.

While the twins may be double the joy, they also can be double the work when it comes to daily routines.

"Moms with multiples have to be very scheduled and routine-oriented," Nealon said. "That's why these children are so well behaved."

And well-behaved they were. Twenty-four children sat in a fairly small space on the floor in the Creek View school library. Most either dressed alike or wore coordinating outfits. All of them sat near the person they're closest to in the world.

"Seeing them all together does make you smile," Creek View Principal Dixon said. "The first few days of school, it was fun to see them arriving holding hands going down the hall or helping one another with their backpacks.

"I have a hard time telling the same gender apart but know the twins of different gender," she said. One set told me their mother could tell them apart by their cheeks, so I guess parents have a difficult time, too."

Join the conversation by clicking to comment or e-mail Kennedy at vkennedy@bhamnews.com.