Nightcrawlers are large, nocturnal earthworms known for their ability to burrow deep into the soil. They are typically found in moist environments and play a crucial role in soil health by aerating the ground and breaking down organic matter. Their movement helps improve soil structure and nutrient availability for plants. These worms are often used as bait in fishing due to their size and wriggling motion, which attracts fish. Nightcrawlers can grow up to 8 inches long and are usually dark brown or black in color. They are an important part of the ecosystem, contributing to nutrient cycling and soil fertility.