WHEN Annikki Dighe lures young kids into her Glen Echo lair, things get down and dirty right away. The youngsters crawl through the creepy dark. They spy on naked mole rats, ogle anthills, pet a prickly hedgehog, squirm past a worm farm and peer at prairie dogs. They dish the dirt about life and death. They go home slightly grubby and, one hopes, with the beginnings of a grounding in the wonders of the earth we all walk on.

Dighe, a senior educator with the Children's Museum of Washington, has the bounce and enthusiasm of an overwound cheerleader. It takes her only a few minutes to learn the names and engage the attention and energies of the dozen or so children she leads on tours of the "Deep Down Underground" exhibit that has transformed the old National Park Service stable at Glen Echo Park into a labyrinth of lighthearted learning. The tours, led by one of the center's eight educators, also include a tramp through the adjacent woods and along a creek.

Equally adept at drawing out shy youngsters and gentling disruptive class clowns, she soon has everyone stepping lightly along to the irresistible rhythm of her earthy delivery. The kids' steps grow lighter still as Dighe leads them to the understanding that the ground beneath their feet wasn't always there, it's a mixture of worn-down rocks and rotted plants and is just crawling with bugs and mold and animals as big as badgers and as small as sand grains. Each child takes on the role of a plant, animal or insect.

Dighe and her seven fellow educators have a canny knack for winkling out who'll make the best Dead Dude or Water Warrior. At some point during the tour, each child takes a star turn as a key element of the ecology; by the end of the exercise comes the understanding that all elements of the ecology are essential. Along the way they are matter-of-factly reminded that death is a natural and inevitable part of life's loamy underside.

The exhibit, which is open to the public on weekends, is the current attraction of the nonprofit museum's Discovery Creek unit, now in its second year of operation. The museum designs its programs specifically for pre-kindergarten through sixth-grade children.

"We have an awful lot of fun because we get children at their brightest and most open-minded age" says Jacqueline Eyl, director of education. "And it's the critical age: If we can turn them on to nature now, they'll probably never turn off."

The teaching method is not only hands-on but hands-in: Hands in a rotting stump to feel wood turning to soil; hands in the creek to feel the slime of algae and the grit of sand starting on its long journey to the sea; hands scrabbling through crisp, fresh-fallen leaves to find the remnants of last season's shed glory, now almost fully decomposed in Mother Earth's recycling center and well on their way toward renewal and rebirth as part of other plants and animals.

Most of the weekday visitors come by school bus, and the pent-up energy of the regimented ride is dissipated in a swimming pool-size sandbox in the stable yard, where they cavort in athletic abandonment while awaiting their turn to tour. Through a marvelous grasp of group dynamics, the center's tour leaders manage without sternness or yelling to channel the children's joyful abandon into eager examination of the world beneath their feet.

The museum, founded in 1994 in Washington's last one-room schoolhouse, an 1864 structure at 4954 MacArthur Boulevard NW, has formed partnerships with 20 District schools, 10 more in Montgomery County and expects to expand to schools in other area jurisdictions, particularly those with a large percentage of disadvantaged pupils.

The museum's mission, says Eyl, "is as clear and simple as it can be: We try to help young children understand that they're part of the living planet; that food doesn't really come from the Safeway, that trash doesn't just go away, that we share the earth and air and water with other living things and all are important and valuable. Kids used to experience nature as they grew up, but America has been urban for several generations now, so they grow up in a largely artificial, televised, computerized, virtual-reality, keep-off-the-grass world."

While the center makes the learning process painless, all its programs meet national scientific instruction standards, Eyl says. Other offerings include after-school and weekend activities and summer science camps. Eyl's pet project of the moment is a "Rolling Rain Forest," a self-contained, living and functioning ecology exhibit in a tractor-trailer rig that can be driven to schools.

Adults are welcome to join their children in the underground adventures, but are warned to watch out for low ceilings: The environment is geared mentally and physically to little visitors.

DEEP DOWN UNDERGROUND -- On view weekends through Jan. 30 at Glen Echo Park, 7300 MacArthur Blvd., Glen Echo. 202/364-3111. For children 3 to 11. Open 10 to 3 Saturday, noon to 3 Sunday. Admission $4, adults free.