Take a walk on a damp morning following an overnight rain and worms will likely be crawling on the sidewalk
Nightcrawlers and other worm species are common in rural and urban areas throughout much of North America. Worms are so abundant that most people are amazed to learn that they are not native.
Most worm species originated in Eurasia and were inadvertently brought to this continent in soil surrounding nursery stock. Tiny eggs may have hitchhiked across the ocean in scraps of dirt. No matter how they got here worms arrived in early settlement days and quickly spread.
Nightcrawlers are the most visible worm species because they are large and often come to the surface. Most other species stay below ground. Crawlers are the most common worm sold for fish bait, and anglers dumping extra ones on the ground probably helped this animal expand its range.
Worms are frequently praised for their ability to aerate soil and break down plant residue into “castings”, or worm manure. Plants readily use this fertilizer, making worms the friend of farmers and gardeners. There’s no doubt that mixing by millions of earthworms helps make soil soft, rich and permeable to water. Ecologists take a dim view of these exotic invaders, which can reduce forest leaf litter and alter plant life in pristine ecosystems.
Going “nightcrawling” is a fun activity for children, whether or not the family goes fishing. Nightcrawlers come to the surface on damp spring nights to mate. Each individual is both male and female, and two join together to swap sperm before laying eggs. Visit the lawn after dark on a drizzly evening and quietly shine a dim flashlight’s beam on the ground. Two worms lying next to each other are likely mating. Leave them alone but gently grab any single worm and drop it in a can for future fish bait. Often a crawler will keep its tail in the ground. If a gentle pull doesn’t free it briefly stop tugging, and it will likely relax its grip and be easily captured. Be stealthy. Worms are spooked by vibrations in the ground, so wear soft shoes or go barefoot and move quietly.
Fish, birds, and many other animals eagerly devour worms, and they are now an important ecological component of lawns, gardens and farms.
