Make the season when the birthday child was born the theme for a party, and mimic nature's decorations -- snowflakes for a party in winter, perhaps; flowers for summer. Bugs crept into our spring party.
The invitations, clear tubes with slips of paper and plastic insects inside, resemble a bug scientist's project. Hot-glue plastic ladybugs to party hats. For a centerpiece, more plastic critters crawl over fake moss and inside jars (with holes punched in tops, naturally). Hang leafy garlands cut from tissue paper. Earthy-looking parfaits stand in for a traditional cake; they're made from chocolate cake, whipped cream, crushed cookies, candy rocks, and mint sprigs. As favors, guests get to take home collector's boxes with rubber insects and bug-shape pens.
Lined specimen boxes are available at hobby stores. To cover box: Remove glass; set aside. Lay a piece of wrapping paper (a few inches bigger than box on all sides) right side down; coat top of box lid with rubber cement; place face down on paper. Cut away center of paper by running a utility knife along opening. Wrap paper over sides of lid, affixing with rubber cement; cut away extra. Replace glass. Affix labels with names. Fill boxes with rubber insects and pens.
Print invitations and cut into strips; roll inward, so they can't be read through the clear mailing tube. Place a plastic bug and fern inside. Affix address label and postage to outside.
Print template. Cut a strip of tissue paper as wide as template is tall. Accordion-fold tissue, making layers same width as template. Lay template on top (dotted lines on folds); cut out leaf along solid lines. For longer garland, tape two together.