A more whimsical outdoor activity is building a habitat for tiny mythical creatures -- fairies. You can use household and craft materials like milk cartons, paper towel rolls, popsicle sticks, fabric, clay, wood glue or anything else that's relatively biodegradable, but the beauty of fairy houses is that you can also make them entirely out of materials gathered from the outdoors; think rocks, sticks, bark, leaves, grasses, vines, flowers, feathers, pine cones and shells. Just be sure not to include anything that might harm animals like small plastic items or metal staples, and try to gather fallen items rather than ripping up live bark or foliage.
You can build your fairy house next to a tree or other natural barrier, in a garden or park or anywhere in your own yard, and make it blend with the surroundings. You can use a milk carton for a base, or you can go entirely natural and make walls by stacking rocks or implanting sticks or bark into the dirt. Then lay a roof with bark or twigs and make a floor with bark, pebbles or leaves. Sticks, bark and pinecones can be used to make fences, and lots of tiny pebbles make a nice pathway. Placing your fairy house over moss would make for a nice built-in floor or lawn, as well.
Get fancy by making tiny furniture out of the same materials. Flowers, pinecones and nut and acorn shells also make nice decorations. Fairy houses can have doors and windows, archways or open sides so that you can easily place furnishings inside. You can even combine this craft with container gardening and creating a fairy habitat in a planter, replete with fairy-sized plants, tiny furniture, pebble paths and the like.
You and your little ones can have fun designing, building and furnishing the dwelling, then imagining the future fairy inhabitants. Trying to give your fairy house structural integrity might help prepare your little ones for futures in architecture or engineering. But it is sure to be loads of fun, too.