Every Wednesday, Davis students are asked to try and bring their lunches to school in reusable lunchboxes, containers and drink holders instead of in disposable single-use ones, said parent Lisa Manfredi, who dubbed herself "EcoMom."
Manfredi has been working to "green" the students' lunches by getting them to compost any remaining lunch waste, recycle and "upcycle," the latter being finding a better environmental use for a used product, she said.
The idea was to make them more aware of what they use, Manfredi said.
"We're just kind of reducing our footprint," she said. "It's coming along."
Manfredi checked students' lunch containers before they started eating and handed out green paper "Duck Dollars" as a reward to those who used eco-friendly containers.
The dollars can be redeemed in teacher's prize boxes.
Six-year-old Dillon Morgan said they can also be used in the school store to buy things like Popsicles.
During his presentation, Carey reinforced what the students have been learning by providing them with visual aids for what constitutes an environmentally-friendly lunch container.
He also gave them a visual, hands-on display of how the average person wastes plastic grocery bags, which some cities like Santa Monica are banning.
The average adult uses 500 plastic grocery bags a year, Carey told the students as Manfredi started pulling 500 plastic bags tied end-to-end out of a giant cardboard box.
Students jumped up to help stretch out the chain until nearly everyone had abandoned their lunch.
The chain kept coming and coming as it wrapped around the lunch area, with students going nuts over how long it was.
"Oh, my God! It's still going," one boy screamed in excitement.
Dillon said she already knows Carey, having visited the OCC Recycling Center in preschool, and liked what he had to say.
"I thought about it," she said. "I liked it because it's recycling. I like recycling because I want the world to be more clean than it was earlier."
Davis PTA official Susan Sarte said she has seen Manfredi's efforts working first-hand on her own son, who asked her to pack a waste-free lunch that week.
"It's cool," she said. "It's making the kids aware of it."