Thirteen children, ages 5 to 9, were given a task of finding something biotic - living in nature - and placing a donut-shaped piece of cardboard around it.
Chloe Fornoff, Eden Fornoff and Syvia Weiskopf took the ring and walked down a path to a tree with branches that hung straight out on either side of its trunk.
"A tree is biotic," Chloe, 7, of Whitehall, said to Eden and Syvia. They agreed. Repeatedly, Chloe jumped up and down trying to hang the ring, but the branch was too high. Finally, she settled for a lower branch. She hung the ring on its end, and the girls joined their group.
The outdoor search for biotic items was one of the activities in which the children participated during a recent 90-minute session. The class is part of a four-week long home-school program called "Ecosystems" being offered at Eden Mill Nature Center.
The idea to start the program came after a number of parents called the nature center looking for affordable enrichment programs for their home-schooled children, said Amy Harris, the center's head naturalist, who created and helps teach the classes.
"We try not to be the run-of-the-mill nature center," said Frank Marsden, program director at Eden Mill. "We offer programs that are for children through adults. We find time-tested programs that work and offer them every year, and then we try to offer new programs each year as well."
Each session of the class is broken down into two parts - an indoor lesson that includes review of homework, and an outdoor portion that gives the children a chance to explore and learn about the ecosystem.
The class costs $27 for non-members, $24 for members and $20 for additional children from the same family.
In the first ecosystems class, the children learned about and then explored animal habitats, Harris said. Based on the Maryland Department of Education standards, the curriculum includes components of habitats -- food, water, shelter and space; and the five types of habitats, she said.
"We took the children out to see the types of habitats that they would see in Maryland, forest, meadow and wetlands," she said.
On a recent morning, the children gathered inside the nature center where they were allowed to look at the animals. They rubbed the fur of the animals that included birds, a beaver, a black bear, a fox and a muskrat.
Elijah Weiskopf, 6, of Street, was captivated by the animals.
"There are two turtles in the water, but don't try to touch them, they are snappers," Elijah told some children who had gathered around a small man-made pond.
After a few minutes of exploring in the nature center, the children sat in a circle for their indoor lesson. They learned about biotic and abiotic items.
Using two hula hoops - the pink one to represent nonliving items and the green one for living items - Stephanie Close, a seasonal naturalist at Eden Mill, explained to the children that biotic items were living, and abiotic were nonliving things.
Then, one by one she picked up items - a stuffed animal, a banana, plant, plum, flower, rock, seashell, and plastic beads - and had the children say whether the items were biotic or abiotic. As they answered, she placed the items in the appropriate ring.
When she got to a book, the kids hesitated.
"What would this book be - biotic or abiotic?" Close asked.
"Biotic," one child answered.
"What is the paper in the book made from?" she asked.
"A tree," another child answered.
"And what are trees - biotic or abiotic?" she asked.
"Biotic!" several kids answered.
After the children reviewed their homework, they bundled up in their jackets and went outside to explore.
The outdoor exploration was a big selling point for some parents.
When Kara Cox, 42, of Bel Air, heard about the outdoor portion of the program from another mother who home-schools her children, Cox signed up her son Ryan, 9.
"Boys love animals, they love to get dirty, and they love to be outdoors," she said. "I think it's wonderful for children to have this opportunity to be outdoors to explore the ecosystem."
Ryan agreed with his mother.
"I like it because I get to be outdoors," he said. "It makes it fun. You can learn a whole lot about nature and stuff if you are outside."
Deana Fornoff brought her daughter Chloe, 7, and her niece Eden Fornoff, 7, from Delta, Pa., to participate in the program.
It's organized, well-planned, and affordable, Fornoff said.
"We really have to look to find home-school programs," said Fornoff, 32, who has been homeschooling for two years. "They offer programs at museums and the aquariums, but they can be expensive."
Tammy Cowan, 27, of Pylesville, saw the program as a chance to get her two sons Titus, 6, and Jude, 5, to the nature center, she said. Although she grew up nearby, she said she had never been to Eden Mill.
Titus said he has enjoyed being there.
"I have learned a lot about habitats and animals," Titus said. "It's really neat to go see where animals live."
In the final two classes, the children will learn how to determine if an ecosystem is healthy, and ways to help prevent habitat destruction.
A second class will be offered starting on April 28, called Water Wonders. During this class the children will learn about watersheds, the wetlands, and conservation.
For more information or to register for the next class, call 410-836-3050 or visit www.edenmill.org.