Source: Science Art

Butterfly Symmetry

Students explore symmetry in nature by making bright butterflies.

Science Talk
Look closely at a butterfly's wings and you'll see that each is made up of thousands of overlapping, iridescent scales — a shining example of symmetry in nature. A line of symmetry divides a shape into two identical parts. In some cases, as with a butterfly, you'll find one line of symmetry. In other cases, there is more than one — as with eight sections of an orange.

Materials
books about butterflies
old newspapers
round coffee filters or paper towels cut into 9-inch circles (1 per student)
food coloring in squeeze bottles (several sets)
plastic cups (1 per student)
water
spring-type clothespins (1 per student)
pipe cleaners
wiggly eyes and glue (optional)
smocks

1. Gather assorted books about butterflies and let students get together in small groups to read about these colorful insects and study the patterns on their wings. Bring students together after a while to discuss how the patterns are useful to butterflies (camouflage, alert predators that the butterfly is poison, attract a mate).

2. Ask students to describe characteristics many butterflies have in common (bright colors, distinctive markings and patterns, wings are the mirror image of each other).

3. Invite students to create their own butterflies. First cover work surfaces with newspapers. Divide students into groups. Give each group bottles of food coloring to share. Each student will need a cup of water and a coffee filter.

4. Show students how to fold the coffee filter in half, then in half again. Demonstrate how to dab designs on the folded filter, using different colors and shapes (such as rings, dots, or lines). Then let students get started on their own designs, replicating patterns from a real butterfly or making up their own.

5. When students are finished making their designs, show them how to set the folded tip of the filter in the cup of water. Have students observe what happens. (Thanks to capillary action, the filter soaks up water from the cup; as water reaches the colors, they begin to bleed into one another.)

6. After a few minutes (or when the water has completely soaked the filter); have students remove the filters from the water, open them up, and spread them on newspaper to dry. Ask students to describe how the colors changed. What do they notice about where the patterns appear? (The colors soaked through the folds of the filter, creating mirror-image, repeating patterns all around the circle.)

7. When the filters are dry, hand out clothespins and pipe cleaners. Guide children in following these directions to make their butterflies.

  • Pinch the filter together in the middle, then slide it into the clothespin and spread out the wings.
  • Insert small pieces of pipe cleaner into the front of the clothespin for antennae. Glue on wiggly eyes (optional).

Book Break
The Butterfly Alphabet by Kjell B. Sandved (Scholastic, 1996) features spectacular close-up photos of butterfly wings, each revealing a pattern that resembles a letter of the alphabet, from A to Z. Facing pages show what the entire butterfly looks like. An annotated glossary in the back of the book gives information about each butterfly featured.
     For a creative writing break, share "How Butterflies Came to Be," from Keepers of the Animals by Michael J. Caduto and Joseph Bruchac (Fulcrum, 1991). Then let students work in groups to write their own butterfly stories.

Extension
Symmetry in Nature: Collect a variety of symmetrical and nonsymmetrical objects from nature, such as flowers; rocks; maple seeds; leaves; feathers; shells; mushrooms; and apples, citrus fruits, and onions (sliced in half). Use a pocket mirror to classify the objects as symmetrical or nonsymmetrical. (Place the mirror on the center of an object. If you see the mirror image, the object is symmetrical.) Dip symmetrical objects in paint and use them to make prints.