diy giant squishy sensory bag: clear plastic, duct tape, food coloring, and water = fun way to cool off on a hot day without getting wet + fun for babies and kids (and adults) soooo making this in summer
Colored water in squeeze bottles for drawing in the snow. Totally doing this this winter. Science and Art grade Teach a lesson on the weather changes outside. Then take the kids outside and paint the snow with these colored water bottles
Make your own Sponge Water Bombs (alternative to water balloons). Cut sponges in strips crosswise, then stack 4 wide, 2 deep and tie very securely in middle with fishing line. Soak, play, have sponge water fight!