If you walk through a Hall County school these days, you may think you're seeing double.

Most schools are reporting an abundance of twins this year, and even a few sets of triplets.

Rick Quarles, principal of Sugar Hill Elementary School, never gave it much thought until recently.

"We just started noticing we have a bunch of kids that look alike running around here," he said. "I've been in education for 24 years and have not seen this amount before."

A head count revealed six sets of twins, ranging in age from prekindergarten to third grade. Then Quarles learned that physical education teacher Shauna Sudderth is pregnant and expecting twins next spring.

He said he wasn't sure whether the incidence of twins is really increasing or if it's just his imagination.

It's real, according to statistics from the March of Dimes. Between 1980 and 2003, twin births increased by about 66 percent, and the incidence of higher-order multiples (three or more babies) increased by about 400 percent.

About one-third of the increase is attributed to the fact that more mothers are delaying childbearing. Older women are more likely to have twins. But the rise in triplets and larger groups of multiples is almost entirely due to the popularity of fertility treatments, which often result in more than one fertilized egg.

Most twins are fraternal, meaning they come from different eggs and are genetically no more alike than any other siblings. Identical twins come from a single fertilized egg that splits during early embryonic development.

But young twins often look strikingly similar to each other, even when they're fraternal. Child actresses Mary-Kate and Ashley Olsen, for example, played the same character on TV but were actually fraternal twins.

Quarles said in the lower grades, parents tend to dress their twins alike.

"But their personalities are very different," he said. "Even with identical twins, their classmates don't seem to have any trouble telling them apart. And the teachers who know them learn to recognize small differences to distinguish between the two."

There has been a long-standing debate about the best way to educate twins. The conventional wisdom was that they would learn better if they were placed in separate classes.

But last year, Georgia parents of multiples successfully lobbied for passage of a state law that allows them to choose whether they want their twins in separate classes or not.

"We try to honor the parents' request," Quarles said. "Three of our sets of twins are split up, and three are in the same classes."

Student placement can be something of a juggling act when a school has many multiples. Chestatee Middle School, for example, reports at least nine sets of twins and two sets of triplets. And by law, class size cannot exceed a certain number of students.

But Gordon Higgins, spokesman for Hall County Schools, said the schools generally are able to accommodate a family's wishes.

"It's usually not a big deal," he said. "If parents request that their twins be in the same class and you're at maximum class size, you just switch another kid out."

Quarles said if he were a parent of twins, he probably would want them to be in the same class.

"That would make it easier to help them with their homework, because they would have the same assignments," he said.

As twins get older, they typically develop their own interests and want to assert their independence from each other.

"During their first semester here, siblings usually like to have the same lunch period," said Jaclyn Hatrack, a counselor at Flowery Branch High School. "But once they get acclimated, they're comfortable being on their own."

She said some twins seem to relish their "twinness," knowing that it makes them special.

"Some still dress the same," she said. "Most of them seem to love being twins."

But they also may resent being always referred to as "the twins" rather than recognized as separate people.

Things can get especially touchy if one student is a high achiever and the other is not.

"With some sets of twins, there's competition between them," Hatrack said. "We try to emphasize their individuality and show them that each one of them has their own strengths."

One of the toughest situations occurs when one twin gets promoted to the next grade and the other one has to repeat the academic year. Both Sugar Hill and Chestatee Middle have cases like that.

Hatrack said Flowery Branch doesn't have any split-year twins, and she hopes it doesn't happen.

"From a psychological point of view, it would be difficult for them to deal with being in separate grades," she said. "It would certainly be a blow to the self-esteem of the child in the lower grade. If I were a parent of twins, I think I would try to put the child in summer school and do whatever I could to help him catch up with his sibling."