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Information on Nightcrawler Worms

The night crawler, also known as the common earthworm or by the scientific name Lumbricus terrestris is frequently divided into three categories, the European, African and Canadian. However, this is not quite accurate as the worms were introduced to Canada from European sources. These worms are native now to most of the northern hemisphere and can measure up to 25 cm in length.

Biology
- An earthworm's body is basically a tube, with a digestive tract which runs all the way along it. It has a brain and heart, which are located at the head end, but no eyes and ears. There is little to see or hear underground, however, to make up for it, the nightcrawler has light sensitive cells along its body and can sense vibrations in the soil. It also does not have lungs, but absorbs oxygen directly through the skin into the blood stream. If a worm becomes dry, it dies of suffocation.
Movement
- Nightcrawlers move through the process of peristaltic contraction. Worms can expand and contract the fluid filled segments which make up their bodies. First an earthworm expands these rings to anchor itself in the narrow tunnels in which it travels. It then elongates the leading end segments. The leading end indicates the direction the worm wants to travel in, forward or back, and is not necessarily the head. With the segments elongated in the direction it wants to travel, the worm then contracts the anchoring segments, pushing the leading end forward and dragging the trailing end along.
Life Cycle
- Night crawlers have both male and female sex organs but must still mate with other worms to reproduce. To do this the worms lie next to each other and transfer sperm to one another, then both worms lay eggs in capsules. Each worm may lay eggs several times per year, but the primary mating seasons occur in rainy seasons when the moisture levels are the highest. Each worm may produce 10 to 15 offspring per year and a nightcrawler may live for as long as 10 years.
Feeding
- A nightcrawler feeds while moving, swallowing organic matter -- and soil containing organic matter -- and then passing it through its body. Its long digestive system removes nutrients as the matter passes through before the waste is passed through the other end. Worms are attracted to moisture and cool temperatures. By night they move near to the surface of the soil where there are more nutrients, but during the day they burrow down away from the heat. Earthworms will actually leave the soil after a rain, though the reason for this is unclear.

Nature