At fourteen, Robert Moering of Reston is already living in the past -- as the son of a poor tenant farmer in the colonial period.

"It's 1773 to be exact," says his pretend father, Gary Dye, at the Claude Moore Colonial Farm in McLean. "Except for those damn planes going into National Airport," he grins while pointing at a passing iron bird, "the 20th century has been left out."

"The kids don't talk 20th century here," he continues. "They can't talk about video games."

It's all part of the effort to recreate life in the mid-1770s at the farm, a 12-acre window on the past. A timber barn for drying corn and tobacco stands in a hand-tilled field. Turkeys roam the fields near a primitive log cabin typical of the homes of 75 percent of the colonists of that era.

Moering and his "brothers and sisters" -- some 22 kids ten years and older -- help complete the picture by volunteering to work on the farm on fall weekends and describe the life to visitors in 18th-century language. Many of the volunteers work in the spring and summer too. About half a dozen kids are on hand each day at the farm, also known as Turkey Run.

They spend their time working the worn- out land of the tobacco and corn fields and the small "kitchen garden" where vegetables are grown, chopping and carrying wood, mending fences, cooking, baking bread and tending to the lifestock. There are plenty of chickens, bronzeback turkeys, razorback hogs, cattle and a quarter horse.

"The biggest job around here is the weeding," says Moering, a sophomore at Herndon High School. "We could be doing more of some of the other work that needs to be done around here like fence mending and chinking (caulking the log cabin), if it wasn't for all the weeds.

"While weeding, I think about how important it is. When it's hot I think 'Why am I doing this?' And then I wonder if 18th- century weeds were this bad."

They probably were. The only insecticides used by early American settlers were turkeys who were fed so much corn that they couldn't fly. They were then led into the fields to eat tobacco worms off the plant leaves.

Another important job performed by the kids is the removing of "sucker" starts from the tobacco plants. "Suckers" are secondary shoots that sprout constantly through the growing season.

"These little things have to be plucked about every two days," says Dye, tugging on one of the sprouts. "In colonial days, some farmers replanted the starts. If he was caught growing a 'sucker' crop, the entire field would be burned by the militia."

"We really need their labor," says Anna Eberly, who manages the farm. She was one of the organizers when Friends of the Claude Moore Colonial Farm at Turkey Run was formed. With the help of private donations, the group saved the operation after the National Park Service bowed out in 1981.

"Some of the visitors think we have the kids because they look nice, but they really do a lot of the work," she says. "We couldn't make it without them."

Eberly figures that today's volunteers are not as well equipped for farm labor as their 18th-century counterparts "but they have a lot better social skills. They know how to talk to people."

"We eat vegetables from the garden, bread, and sometimes we eat meat," says Moering.

Where does the meat come from?

"From the pigs!" Then, grinning, he whispers in his 20th-century voice, "Actually we go to Safeway and buy it."

All of the Turkey Run animals are considered pets and are not sold or slaughtered.

Women do all the cooking. The girls or "daughters" help all the "mothers" with their chores and also work in the fields.

"I do everything the adults have to do but in smaller quantities because I'm younger," says ten-year-old Joanne Seiff of Falls Church. "I do just what my 'mother' would do but in a smaller fashion.

"If you're a girl -- it's kind of bad," says Seiff. "You don't like to spend a lot of time hanging over the fire and get all that smoke in your eyes. It gets especially hot in the summer."

Seiff made all of her own period linen clothing. "I did it on-and-off in about two weeks," she says proudly, while acknowledging that she used a sewing machine for the inside stitches. "But all the outside seams were done by hand."

Women don't take care of the animals except for the chickens. "The other animals are too large for them to handle," points out another child.

Most of the farm animals roam the farm freely. In colonial days, "fencing out" unwanted company was the pattern. But at Turkey Run, the ox is kept in a fenced pasture, protecting guests, and chickens are now kept in a coop at night for protection. McLean still boasts of roaming foxes and raccoons that find the fowl tasty.

With all the hard work -- work days for the kids are eight hours long -- comes a little fun. They sometimes play Indian games like "Ball in the Cup" or make and play with dolls made of corn husks.

Their response to farm life is almost always the same. "It's exciting!" says Moering, who had never farmed before last May. Now he knows all about tobacco and farm animals. His friends jokingly call him "Farmer Bob."

"I like that. It fits me," he says. He's now studying the 18th century in school, finding it easy to learn and hoping one day to be a paid staff member at the farm.

He's not alone. "I think I'm going to do this for a while," says Seiff who has no interests in today's electronics but loves history. Her future lies in the past.

Of course, the kids have their complaints, too. Walter Reed, 12, has a problem with his handmade shoes. They're designed for either foot for longer wear, and would cost more than $150 a pair to replace. "They're kinda old and the nails hurt," he says holding up a ripped shoe as proof. "They don't work that well."

"Sometimes the work is really hard, sometimes it's not as hard," adds Moering, "but it's always fun. It's also better than hanging out on the streets and getting into trouble." DOWN ON THE FARM -- From the George Washington Parkway take Route 123 toward McLean, then right on Route 193 to the farm. Hours: 10 to 4:30 Wednesdays through Sundays from April to November. Adults $1; Children 50 cents. 703/442-7557. The park will host a Market Day of period goods on September 17 (raindate is September 18).