Red Worms Are Coming Up in My Lawn

Rain

• When it rains, water seeps down into the soil, filling any spaces that are there. This includes the burrows that worms make. Since worms can't survive underwater, if there is so much rain that their tunnels flood, they must either come to the surface or drown. The same thing happens when a lawn is watered. It is very common to see worms after a rainstorm, or even while it is raining, as they come up in the lawn to escape the flooding of their tunnels.

Chemicals

• Chemicals applied to a lawn may irritate the worms living there. According to the University of Illinois, as many as a million earthworms live in an acre of land, so it is not surprising that some of them will come to the surface in response to something that infiltrates the soil and causes them discomfort. Fishermen use this trick to catch deep-dwelling night crawlers, applying some diluted mustard to the soil and sitting back and waiting for the worms to appear.

Food

• Red worms have to eat, and many types will come to the surface to feed. In an area such as a large, open lawn, the red worms that come up are often night crawlers. These large worms will crawl over the surface until they find food items, such as dead leaves, and drag them back to their burrows to consume at their leisure. This not only benefits the worms but it also brings important nutrients down below the surface of the soil.

Hazards

• When red worms are seen coming up in a lawn or other area, it is often at night. They are spotted only because there is moonlight, streetlights or other illumination. Worms avoid being exposed to daylight if at all possible because they cannot tolerate light for long. If a worm comes to the surface during the day to escape drowning, or for any other reason, it must get back into its burrow as quickly as it can. If it is exposed to the light for an hour or more it will become paralyzed by the light and die.