Scientists believe that earthworms were probably brought to the United States by European settlers.  They are located all over the world now and have adapted to where they live.
    Earthworms can be from an inch long to twelve feet long but most are from eight to ten inches.  Their body is smooth, reddish-brown, and is made up of a tube that looks like it’s inside another tube.  They don’t have eyes or ears but do sense heat, light and touch.  Since the earthworm doesn’t have lungs or gills, it breathes through its skin.
    Worms move around by stretching out their front body and pushing through the soil.  Then they pull their back parts up toward their front half so they aren’t stretched anymore.  They begin to do this again.  That is how they move from place to place.
   Earthworms are hermaphrodites which means that they are male and female at the same time.  We thought that was strange but then it got even stranger when we found out that it still needs another worm to make eggs.  The eggs are laid in a cuff-like part that goes around the worm body.  The cuff slides up and off of the worm’s body and forms a cocoon.  The earthworms hatch in a few weeks.
    Earthworms are important to the land.  They loosen up the soil and put air into it.  The soil grows things better because of this.  They eat the dirt as they crawl through it.  Their bodies digest the plant parts of it and get rid of the rest.  This also makes the soil better.
    Earthworms—like other animals—have learned to adapt to where they live.  They are hibernators and estivators.  When it starts to get cold, the worm will dig down below where frost will reach them—sometimes seven or eight feet into the ground.  They stay there until it warms up outside and then they come back up to the surface. 
    Just the opposite, worms can’t live with too much heat, light or drought.  They go into estivation to get away from these things.  Estivation is a summer time hibernation.
    Earthworms can’t have too much water, either.  They can drown if the soil gets soggy.  Most of the time they are in the first couple of inches of dirt and come to the surface at night.  This is why they are sometimes called nightcrawlers.