Earthworms nearly covered local streets and sidewalks during last week's rainstorms, but the phenomenon is nothing to worry about. In fact, water flowing on a hard surface is like a freeway to a nightcrawler - allowing the worm to reach destinations that would be impossible over dry land.
Think of the way earthworms move through water as "riding the wave." Worms do not swim, but they travel with the water to new locations in search of food and new mates.
The commonly held belief that worms come to the surface for air is only partly true. Earthworms need oxygen to live, and they breathe through their skin by absorbing oxygen from air pockets within the soil. Water fills all of these air pockets during heavy rains, but usually only for a short time. A worm only needs to come up for air if the soil stays saturated for an extended period.
Dead worms found in days following heavy rain more likely died from being too dry than too wet. Since worms do not have eyes, they cannot see which way to go to get from the sidewalk to the soil once the water recedes. A worm dies when its skin and protective layer of mucous dry out. If you find a worm on the sidewalk after a storm, pick it up and toss it back into the yard or garden.
There are many other playground tales about worms. Here are some facts to clear up the misconceptions:
¢ Earthworms that are cut in half will not regenerate both ends. The head end does indeed grow a new tail, but the tail cannot grow a new head unless only the very tip was lost. Even then, it is hard for a tail to regenerate, so if you cut a worm, you will likely still have only one worm.
¢ Earthworms ingest dirt as they eat, but they are actually eating organic matter - fallen leaves and decaying roots and stems of plants. Worms have very strong muscles around their mouth (no teeth) that help the mouth to act like a straw.
¢ Even though earthworms have no eyes, they can sense light and will try to move away from it. They also sense vibrations in the soil.
¢ Earthworms are cold-blooded, but they can freeze to death if the temperature drops too quickly. Protect the earthworms in your flowerbeds and gardens with a protective layer of mulch.
¢ Not all earthworms are the same size. Different species range in length from a few millimeters to several feet. The longest earthworm ever recorded was found in South America and measured 22 feet from nose to tail.
¢ Speaking of species, there are more than just nightcrawlers and common field worms. There are approximately 2,700 different kinds of earthworms worldwide.
¢ Nightcrawlers are native to Europe. They were brought to the United States in the soil of potted plants carried over on ships in the 17th and 18th centuries.