Nightcrawlers (Lumbricus terrestris) are one of the largest earthworm species commonly found in North American and European soils. They are used primarily as live bait for freshwater fishing, but also for composting and as a natural food source for various pets. Extracting these nocturnal worms from their deep burrows requires specific techniques. Successful collection depends on manipulating light, moisture, or ground vibration to encourage them to leave the soil.
Nighttime Hand-Picking Strategy
The most direct method involves collecting nightcrawlers after they have emerged onto the surface following sunset. Success relies heavily on timing and stealth, as the worms are highly sensitive to light and ground vibrations. The best time to search is shortly after dusk on a warm evening when the ground is moist from recent rain or heavy dew, which encourages them to leave their burrows.
Using a light source is necessary, but it must be one the photosensitive nightcrawlers will not easily detect. A flashlight or headlamp fitted with a red filter is recommended, as the worms are less reactive to light in the red spectrum. Movement must be slow and deliberate to avoid creating vibrations that cause the worms to rapidly retract.
Once a nightcrawler is spotted, grab it quickly but gently near the soil line before it retreats, as the tail end is often still anchored inside the burrow. If the worm resists by anchoring itself with small bristles, pulling slowly and steadily will usually extract it without tearing the body. Sudden movement or bright light exposure will cause them to vanish instantly, necessitating patience and practice.
The Flushing Method
An alternative technique is flushing, which involves saturating the soil with a liquid to irritate the worms and force them to the surface. Soaking the ground with a hosepipe until the area is waterlogged can be effective, as the worms emerge to avoid drowning. However, this takes time and is not always guaranteed to work in all soil types.
A more reliable flushing agent involves a mild, non-toxic irritant, such as a solution made from ground yellow mustard seed powder mixed with water. A common ratio is approximately one-third cup of mustard powder mixed into one gallon of water and poured over the patch. The solution creates a localized, temporary irritation that drives the worms out of their burrows within minutes. Avoid using harsh chemicals or detergents, which can contaminate the soil and harm the worms or other wildlife.
Vibration and Sound Techniques
This method, often called “worm grunting” or “worm fiddling,” uses mechanical vibration to mimic a natural predator, causing the nightcrawlers to flee to the surface. Scientific research indicates that the vibrations closely resemble the subterranean movements of a digging mole (Scalopus aquaticus), a major predator of earthworms. The worms mistake the vibrations for a mole and instinctively move upward to escape the threat.
The traditional technique involves driving a wooden stake, sometimes called a “stob,” into the ground and rubbing the top edge with a flat piece of metal, or “iron”. This friction generates a low-frequency vibration that travels through the soil. A simpler approach involves driving a pitchfork into the ground and repeatedly rocking it back and forth to generate similar ground movement. This method is most effective in damp ground, which transmits vibrations efficiently.
Immediate Care and Storage
Once collected, nightcrawlers require immediate care to ensure their survival and maintain their quality as bait or feed. The worms should be placed in a holding container that provides ventilation and prevents escape. Suitable bedding material includes peat moss, shredded newspaper with non-glossy black ink, or commercially prepared worm bedding.
The bedding must be kept consistently moist—damp like a wrung-out sponge—but never saturated. Nightcrawlers thrive in cool conditions, with the ideal storage temperature ranging between 35 and 45 degrees Fahrenheit, often necessitating refrigeration. For longer-term storage, a small amount of food like cornmeal, coffee grounds, or specialized worm chow can be used. Inspect the container regularly and promptly remove any dead or decomposing worms, as they can quickly spoil the bedding and harm the rest of the collection.