Grade 4 Going to have Allie make multiple spinners for the garden this summer. To keep animals away, but also to start her on creating multiple wind turbine designs. Get her trying multiple things to see what she thinks works best.
Here is an idea for a vertical garden in a classroom (plus a fish tank). This could also work in other places -- homes, places of worship, community centres, etc. Maybe even outdoors? With a mesh covering over the fish tank, the cats couldn't get in.