DENVER (KDVR) — Agriculture officials in Colorado are asking residents to be on the lookout for an invasive pest that could be in their yards, right under the soil.
On Tuesday, the Colorado Department of Agriculture issued an invasive pest alert for the Asian jumping worm, an invasive earthworm species. The species, also known as the “crazy worm” or “snake worm,” has been found in several states, including in Wisconsin.
While many earthworms are beneficial to soil, adding nutrients for plants and assisting with soil aeration, the Asian jumping worm does the exact opposite.
“The jumping worms’ hyper-activity degrades the soil structure, can harm plant roots and accelerate soil drying. This creates a ‘nutrient-poor paradox’ where nutrients are present but unavailable to plants. This can further exacerbate drought conditions, which the state is already in,” said CDA in a press release.
The presence of the invasive species was first confirmed in October 2025 in Denver’s Hilltop neighborhood. As a result, the community is being urged to keep a lookout for the species.
There are no effective eradication methods for the Asian Jumping worm, CDA said, but there are a few best practices to help prevent the spread:
- Avoid moving soil, compost or potted plants from yards if infestation is suspected
- Inspect all potted plants and soil before moving, sharing or bringing them into gardens, and consider buying bare-root stock
- When purchasing bulk mulch or compost, confirm it has been heat-treated to at least 130°F for three days to kill the cocoons
If residents suspect an infestation, they are asked to report it to the CDA’s jumping worm reporting form. The agency also has additional information on the invasive species on its website.
The worm has also been found in California, Michigan, Minnesota, Maine, Wisconsin, Iowa, Illinois, Indiana, Tennessee, Ohio, Florida, New Jersey, Kansas, Missouri, Nebraska, Oklahoma, Texas, Louisiana, Kentucky, and New Hampshire.
