Earthworms are not insects, nor are they related to insects. But like insects, they are animals that lack an internal, bony skeleton. They are soft and gentle, and a perfect animal to start interacting with, especially if you are new to "playing with bugs". If you allow your child to dig in soil, they will undoubtedly encounter earthworms. Let your child pick up a worm and hold it. Put some loose, moist soil into a container and place the worm on top. Watch it burrow into the soil. Let your child dig in with their fingers to find the worm again. Remember: earthworms will quickly perish if left in the hot sun. You can teach your child about the importance of habitat by returning the worm to the soil.
While I was searching the internet for interesting earthworm sites to link to this page, I learned a lot about earthworms. For starters, earthworms are not native to the Great Lakes Region! Learn more about earthworms and how you can avoid introducing exotic earthworms into our environment: http://greatlakeswormwatch.org/