The completed caterpillars are not edible, though the materials from this project are made with food. As homework prior to the 100th day, instruct the children to bring 100 pieces of small food in a resealable plastic bag. Good examples include cereal, macaroni noodles or miniature marshmallows. Bring an extra box of cereal to class on the big day in case any of the pupils forget the homework. Hand each child a piece of construction paper and let him or her glue the "caterpillar" segments onto the paper. After the glue is dry, they can draw heads and legs.
This activity requires participation from students and teachers in additional classes. Gather approximately 50 or 100 pupils. Stretch out a long sheet of paper and attach it to a wall using tape. Allow each child to dip her hands in a plate of paint. Offer a few colors from which the children may choose. One at a time, let the children create "segments" of the caterpillar by pressing their handprints onto the paper. If there are 50 pupils, let them use both hands. If there are 100, let each make one handprint. In the likely case that you have extra children, let them create hand print butterflies around the caterpillar.
On the first day of school, attach a paper circle to the wall of the classroom. Draw a face on the paper. Explain to your pupils that this is the face of a caterpillar that your class will be creating throughout the year. Each day, allow a different child to decorate a circle and add it to the growing caterpillar. On the 100th day of school, remove the caterpillar from the wall and return the circles to the children who decorated them. Instruct the children to fold the papers in half, cutting out shapes to create butterfly wings. Hang the "transformed" butterflies from the ceiling of your classroom.
Gather children from each classroom and instruct them to line up, single file, in the school's hallway. Count the children to determine who is the 100th in line. Give her a special decorated hat to wear. Allow the "human caterpillar" to march through the halls, singing a song or chanting a 100th day of school poem. Set up stations throughout the school where the caterpillar can stop to munch on yummy treats, such as crackers, slices of fruit or pretzels.