AT AROUND 9 A.M., one child discovered a gruesome scene and pulled Baule over. “Ah,” she said, beckoning everyone else over. She pointed to the ground, where a pile of dark feathers lay lumped beneath a fir tree. She asked the children to guess who “killed” the blackbird. One small boy suggested that it was maybe the work of a fox. Baule, the school’s director, pantomimed exaggerated thought. “Well, no,” she said. “See how smooth the quill is?” The boy ran his fingers along the feather and nodded. “That means it was plucked. So the blackbird was killed by a bird of prey, not a fox.” She gathered the dirty feathers from the ground and distributed them one by one to the children. A wild-eyed girl with snot dripping from her nose rocked back and forth with impatience and squealed when she finally received her feather.

Within a few minutes, the children were spread out over an expanse of at least 10 acres. Some were jumping from boulders; others were dragging logs through marshland. Most were sucking on filthy icicles that had fallen from the eave of a greenhouse. At Robin Hood, the children are allowed to be out of eyesight of their minders, but not out of earshot. “Being secretive is good for child development,” Peters said. But whenever an adult called out “cuckoo,” the children all dutifully returned from whatever dangerous thing they were doing, which on the day I spent with them included climbing at least 10 feet up a tree and sliding unsupervised across a frozen pond.

“We used to bring very simple things, lengths of rope for instance,” Peters said. “But soon we realized even that wasn’t necessary.” The lack of toys, he explained, means less fighting and more inclusiveness. “They realize that they need friends if they’re going to play.” Just then, Peters bent down and picked a frosty leaf — an English plantain, I later learned. “We use this instead of Band-Aids,” he said, “You just mash it up a bit and stick it on a cut. It has natural anti-inflammatory properties.”