All is quiet in the woods outside Frankfurt on this chilly spring morning until a group of 3- to 6-year-olds appears over the crest of a hill. Dressed in rain gear with small backpacks and rolled trail mats, they leap over fallen trees and narrow streams and puddles while two caretakers haul a small cart of tools and supplies.
Outside the city, the Forest Mice from St. Thomas Kindergarten are on their way to school, al fresco.
This is one of roughly 300 such "forest kindergartens" in Germany today - a trend that is growing quickly. In an age when concerns about obesity, poor concentration, and aggressive behavior run high, many German parents are eschewing computer screens and plastic toys in favor of outdoor education.
While most kindergartners play in heated classrooms and courtyards with slides and swings, the Forest Mice romp in the open air every day of the school year, rain or shine (there is a trailer for extreme weather conditions).
"Parents are more and more aware that consumerism and high technology do not necessarily provide advantages," says Marie Louise Sander, president of the National Association of Forest Kindergartens in Flensburg, home to the first German forest kindergarten, which started in 1993.
"Parents feel instinctively that their children need ... more than a perfect playroom. They need to develop outside the artificially created environment of doll houses and drawing tables," she says.
Unlike many European countries such as France, the Netherlands, and Luxembourg, Germany has no national standards for kindergarten, which includes children ages 3 to 7. Here, ages are mixed, so that 3-year-olds and 6-year-olds play together.
German kindergarten isn't mandatory - children start school at age 7 - but, by law, every child is entitled to a slot regardless of income. Kindergartens are public or private initiatives subsidized by municipal and regional governments. Most children participate.
For St. Thomas students, kindergarten starts at the subway station in Frankfurt at 8:15 a.m. The children meet for a 20-minute ride to the forest, where they will spend the next four hours. (Caretakers are reachable via mobile phones.)
Children hike from the subway to their breakfast area, asking questions along the way. The rules, which include staying within earshot, not picking flowers, and not touching animals, are strictly enforced.
"Look, here's a beetle!" exclaims caretaker Natacha Lautenschläger. She stops abruptly, crawls on the ground, and swiftly pulls out a guidebook as a herd of curious kindergartners gathers around her.
Breakfast, preceded by sharing time, takes place in a clearing, on wooden benches the children have built themselves. Melina has water duty, and holds a bottle so her classmates can wash up. The weather turns cold and Paul, the group's smallest "mouse" at age 3, starts screaming. "Shhh!" says Ute Constant, another caretaker. "You're scaring the little caterpillars!"
Playtime comes next, and children scatter into several groups. The emphasis is on imagination and communication, using nature's supplies for props. Tobias is a soldier; Charlotte a knight. Anne Katherine takes the role of the knight's horse. Each corner of the clearing becomes a learning platform.
"A playground doesn't change," says Ms. Lautenschläger. "A slide remains a slide. But nature evolves and lives. When it rains, there's a small brook to run over; when it snows they can slide. They experience the year's cycles. They can touch and comprehend nature."
Forest kindergartens' greatest contribution is that they instill in kids "an unlimited range of questioning possibilities," says Gerd Schäfer, an expert on preschool education at the University of Cologne. "In an indoor classroom ... the questions kids ask are often those that adults want them to ask, those that link the things in their classrooms." In the woods, he adds, "the likelihood of asking 'What is this?' and 'Where does this come from?' becomes much greater."
Generations ago, children experienced the environment firsthand. Today, they are often driven from one event to the next - from what Roland Gorges, professor of early education at the University of Darmstadt, calls "islands." The links between the islands have become lost in the process. Forest kindergartens give kids the chance to explore with all their senses.
Mr. Gorges says this includes playing in a brook, letting water run down your palms, or floating paper boats on it; smelling flowers; climbing trees.
Forest kindergartens first appeared in Denmark in the 1950s when a Danish mother began taking her friends' children, along with her own, to the woods every day. In the 1990s, Petra Jaegger, a young kindergarten teacher in northern Germany, sought an alternative kindergarten concept. She traveled to Denmark and what she saw convinced her. "A forest kindergarten," Ms. Jaegger says, "means giving kids the chance to remain a child."
Today, Forest Mice are scurrying about in Austria and Japan as well.
After 10 years of experience with forest kindergartens, Germany is producing its first studies. Among the results: The Forest Mice have fewer difficulties sitting still and concentrating than their classroom counterparts. They are less aggressive and report fewer illnesses than other children.
"Parents notice that their children simply feel good," Gorges says. "There's a balance between spirit and body; they have a special sensitivity to nature."
Martina von Winter says that the absence of manufactured toys has fostered her daughter Friederike's imagination and made her a well-rounded child. Sabina Koliqi says the forest kindergarten has changed her daughter Fiona. "She's a balanced person now. There are no goals to fulfill. She can find her inner peace and just be herself."
Concerns that children who spend much of their day in the woods might lack social skills haven't come to pass. "It's demanding," says Marie Sander. "Forest kindergarten means being able to do things that aren't always comfortable."
The lack of mandatory curriculums at the kindergarten level, coupled with a long tradition of encouraging alternative educational concepts, such as the Montessori or Waldorf school philosophies, and Germany's special romantic relationship with the woods, help explain the success of forest kindergartens, says Professor Schäfer. He doubts, however, that forest kindergartens will become mainstream in Germany. Sending every child to the woods is a nice - but elitist - idea, he says. "One can't live only in the woods."
But the influence of the forest-kindergarten movement is being felt on other kindergartens across the country. Preschools are borrowing the concept, introducing "forest days" or "forest weeks" into their curriculums.
Whatever school experiences the Forest Mice have in the future, it's likely they will continue to have a unique attachment to the outdoors.