Have students observe earthworms and redworms. Buy the worms at a sporting goods store that sells fishing supplies. Dump the worms into some dirt in a large tray. Teach the children to gently dig through the dirt until they find a worm. If they are gentle, they can pick it up and let it crawl in their hand.
This activity teaches students how worms burrow in the soil. It is best done outside and then moved into the classroom. Get a small glass or plastic aquarium. Have the children carefully put some gravel in the bottom using a small plastic scoop or cup. Next, they should scoop potting soil into the aquarium until it is 3/4 full. Have each of the children place a worm on top of the dirt. Cover the dirt with dry leaves and a layer of wet dish towels. Cover the entire outside of the aquarium with black construction paper to block the light. Wait three days and have the students watch as you unwrap the aquarium. They will see the tunnels the worms have made. Remove the towels so the students can observe what the worms have done to the leaves. The worms have begun to eat the leaves, turning them into dirt.
Students do not actually paint with real worms in this activity. Before you conduct it, explain to the children that real worms would not like to be used as a paintbrush, so they will be painting with pretend worms. Cook some long, thick spaghetti noodles in water and oil so they won't be sticky. Drain and place the noodles in a bowl for the students. Squirt a small amount of tempera paint on paper plates. Give the students white sheets of paper. Have the children place a noodle in the paint, drag it through, and then drag it across their own white paper as if it were a worm.
Read some library books about worms appropriate for kindergarteners. Have the students lie on the ground and squiggle around like earthworms. They can pretend they are burrowing into the earth and chomping on leaves and plants. Have them try to make the letters "S" and "C" with their worm bodies.
Give each of the kindergarteners 10 gummy worms in a cup. Tell them they can't eat them until the end of the activity. Have them dump the gummy worms on the table and count them one at a time as they put them back into the cup. When the exercise is over, allow them to eat the gummy worms if they wish.
Plastic worms used for fishing lures often come in many different colors. Obtain some, without hooks, in several colors. Dump them onto a table and have the kindergarteners sort them according to color.