Nightcrawlers are a type of earthworm found throughout many parts of Europe and North America. Compared to more advanced animals, their anatomy is fairly simple. They are commonly found in gardens, fields, and lawns, where they perform the important roles of aerating and fertilizing the soil. Additionally, nightcrawlers are a source of food for many different animals as well as a popular fishing bait.
Also known by their Latin name, Lumbricus terrestris, nightcrawlers are native to Europe. It is believed that the worms were introduced to North America by European colonists during the 17th century. Over time, the worms became prevalent throughout many parts of Canada and the United States.
In comparison to more advanced animals, the anatomy of a nightcrawler is rather simple. It usually measures about 6 to 8 inches (15 to 20 cm) in length, and may be up to 0.4 inches (approximately 1 cm) across. The worm’s body consists of a head containing a small brain and multiple hearts, a long digestive tract surrounded by muscles, and a tail. It has no lungs, breathing instead by taking in oxygen through its damp skin. Nightcrawlers also lack ears and eyes, although they can sense both vibrations and light.
Common habitats for nightcrawlers include gardens, fields, lawns, golf courses, and any other reasonably temperate area consisting of a large expanse of moist dirt. They tend to spend most of their time in tunnels they have dug below the soil, although they often come to the surface at night and during rainy weather, a behavior not fully understood by researchers. The worms subsist mainly on decaying plant matter, though they may also eat fecal matter and decomposed insects.
While many find nightcrawlers unpleasant to look at and thus regard them as pests, they in fact perform two important jobs in the soil they inhabit. First of all, their constant tunneling serves to aerate the soil, improving its ability to circulate water and air. This can contribute to the health of grass, flowers, and other plants which may be growing in the soil. Secondly, the fecal waste and urine released by these worms contribute valuable nutrients and minerals to the soil.
Additionally, nightcrawlers are a source of food for many different types of animals, including birds, frogs, and insects. They are also commonly used for bait by many North American fishermen. In fact, some individuals work as nightcrawler harvesters, collecting the worms at night and then selling them to bait shop suppliers.