Mercer Slough Environmental Education Center

A partnership with the City of Bellevue, offering nature-based programs for all ages.


Polliwog Preschool Philosophy

Polliwog Preschool

At Polliwog Preschool we focus on developing the whole child, socially, emotionally, mentally, and physically while initiating them into a lifelong, meaningful relationship with the natural world.

Polliwog Preschool uses the natural world as a frame for teaching science, art, music, math, language and literacy. Our program is play-based and student-driven with time split between our indoor classroom and the diverse habitats of Mercer Slough Nature Park. Our daily activities meet children’s developmental needs while encouraging curiosity, fostering love of the natural world, and developing the whole child.

Our Classroom

We start and end each day in our traditional, indoor classroom, but we spend most of our time outdoors. The diverse habitats of the 320 acre Mercer Slough Nature Park offer countless opportunities for explorations, investigations, and discoveries. Polliwogs have the opportunity to hike through the forest, dip for creatures in a pond, investigate the flow of a stream, wander through meadows, and bounce on a bog. Every day, our Polliwogs spend time outdoors with our staff discovering, learning, and building their large motor skills. Only severe weather will prevent an excursion; if the weather is safe, the children get out in it!

A Typical Day

We adjust our schedule based on the needs of our class, the weather, and our weekly themes, but always follow the same general outline:

  • Arrival: Children greet their friends, say goodbye to guardians, and choose between art, sensory, and dramatic play activities
  • Opening circle: Teachers introduce the day’s theme with a large-group song, story, or game. We check the weather and decide what gear we need to take outside with us.
  • Outside time: Teachers lead hikes to different parts of the park depending on the day’s theme and the children’s interests. Children spend time on teacher-guided nature explorations, group games, and free play. 
  • Snack: If the weather allows, Polliwogs eat snack outside; if not, we return to the indoor classroom.
  • Extension activities: More choice between sensory, art, literacy, and math stations
  • Closing circle: Reflection, songs, stories, sharing.

Example: Last spring, as the weather warmed, we started to see bumblebees on our hikes. Some Polliwogs were afraid, so we spent two weeks learning more about bees to help children feel more comfortable. Here’s what we did on one day of our bee unit, as recollected in the parent newsletter:

“On Tuesday, we began our day by making collages using yellow and black strips construction paper. It was fun to see how different and creative each project became! We also used our digital microscope to look at a dead bee up close, and were surprised to see bits of yellow fluff, called pollen, stuck to the hairs on its legs. Some of us played in the sensory bin, which was filled with pom poms, and enjoyed using tweezers to pick up and sort them by size and color.

At opening circle, we practiced what to do if a bee gets too close to us. It’s tempting to swat at bees, or shout, but the best way to stay safe is to be still and quiet. Our teacher held a bee puppet and “flew” it around our classrooms, and when it got close to us we practiced staying calm.

We hiked to Bunny Field, taking turns holding the bee puppet along the way. We stopped to watch a bumblebee digging a nest, and were excited to realize that she wasn’t trying to sting us! Once we got to the field, one of our teachers drew a big “figure eight” in the dirt. She explained that bees talk to each other by dancing a “waggle dance.” We took turns running around the lines in the dirt while doing silly dances. We also had some free time to look for bugs and bake mud cakes, and a few of us worked together to build a big pile of rocks.   

We ate snack outside, and after we finished, headed back to the classroom. It took us a long time to hike because there were so many interesting flowers and bugs to stop and investigate. In fact, by the time we made it inside, it was already time for closing circle! We finished our day by learning a new version of a classic song called “Bringing Home a Baby Bumblebee.” In the original song, the singer smashes the bee, so we learned a new version that’s kinder. After we finished singing, it was time for our grownups to pick us up.”

Why Nature Preschool?

We’re one of King County’s oldest nature preschools, but since Polliwog Preschool’s founding in 2012, the nature preschool movement has grown exponentially.

There’s a growing body of research that shows how important it is for young children to spend time playing outdoors. Some of the benefits of nature play include: decreased anxiety; improved executive function and focus; more exercise and better physical health; and increased confidence.

Want to learn more? Here are a few articles explaining why play-based, outdoor learning helps set kids up for the future:

Meet Our Teachers

This is Caroline Cook‘s fifth year teaching at Polliwog Preschool. She came to Mercer Slough from North Carolina, where she taught kindergarteners at an outdoor after-school program, took elementary students on field trips to barrier islands, and led guided hikes in the Blue Ridge Mountains. She holds a Masters degree in Environmental Studies from UNC Wilmington, and has worked at camps and environmental education centers for over 15 years. Caroline loves jumping in mud puddles, holding millipedes, and sharing her love of nature with early learners. She will be teaching the morning classes.

Mary-Margaret Greene likes hunting for bugs and learning new plants! This will be her second year as a Polliwog teacher, and she has worked for Pacific Science Center for almost five years, teaching camps, field trip programs at Mercer Slough, and outreach science lessons at schools across Washington. She received her undergraduate literature degree at the University of Georgia and then headed out west to Wyoming, where she earned a graduate certificate in Environmental Science and Education. She then moved out to Seattle and earned a Masters degree in Environmental Horticulture at the University of Washington. Mary-Margaret is excited for another year of learning and adventures! Mary-Margaret will be teaching the Tuesday/Thursday morning class and the 4-day afternoon class.

After substituting in our classroom last year, Rachelle Ruiz-Ortman is joining the Polliwog team full-time. Rachelle comes to us from California’s Bay Area, but not before graduating from WWU with a B.A. in Environmental Education. She’s also been a part of the Mercer Slough’s camps and field trips teaching teams. In her spare time she enjoys setting up her hammock wherever she can or spotting birds with her binoculars and is a nerd at heart. She loves exploring new areas and helping to spark connections to love and protect the natural world. Rachelle will be teaching the Monday/Wednesday/Friday morning class and the 4-day afternoon class.

If you don’t hear from a Polliwog teacher within 2-3 days, please resubmit your application or contact Caroline Cook at



Mercer Slough Environmental Education Center