By Stephanie Stahl

By Stephanie Stahl

PHILADELPHIA (CBS) — Kids are learning through nature, with a school day that allows the students to spend most of their time outside.

Welcome to the ‘Mud Kitchen’ at the Forest Edge pre-school, where 2 and 3-year-olds use their imaginations and nature to create, well, you name it! Eighty percent of the school day here in Haverford is spent outside exploring and learning.

While digging for worms, they learn how important they are to the soil.

“There’s a nature deficit disorder. All the research says children that are outside are happier,” said Meredith Woods, a teacher at the school. Meredith shows the kids how to turn pine cones into bird feeders.

“Everything is a lesson and at this age, you can do counting, you can do letters all outside,” Meredith said.

And if it rains or snows, the kids are still outside.

“Then you wear boots and jackets. There’s no bad days, there’s just bad clothing choices,” Meredith explained.

This group doesn’t get sick much. It’s inside where they’re exposed to germs. Nature and dirt is helping build their immune systems.

“I think it’s very interesting considering he’s three years old and you would think he’s getting dirty all the time, but he hasn’t been sick since October,” said Lena Ryder.

Lena says her son Jack isn’t just getting an education. He’s learning how to entertain himself.

“He doesn’t need to have TV or the iPad or toys. He just makes fun for himself, whether it’s digging in the dirt, making up stories, looking for bugs. He’s just always busy,” she said.

And they even mix in a little culture with a wind chime made of sticks.