Invasive ‘crazy worms’ confirmed in Colorado, and there’s no way to kill them
Apr 22, 2026, 4:11 PM
Between the drought in Colorado and now these worms, at least I’ll have an excuse for my lawn being terrible this summer!
An aggressive, invasive earthworm that thrashes like a snake, devours the organic layer of soil and has no known eradication method has been confirmed in Colorado, state agricultural officials warned Tuesday.
The Colorado Department of Agriculture issued an invasive pest alert for the Asian jumping worm, also known as the “crazy worm” or “snake worm,” urging gardeners, landscapers and nurseries to watch for signs of the species as an unusually early gardening season gets underway.
The department confirmed the presence of the worm in Denver’s Hilltop neighborhood last October and has since received reports spanning from Boulder to Castle Rock.
The Asian jumping worm encompasses three similar-looking species — Amynthas tokioensis, Amynthas agrestis and Metaphire hilgendorfi — native to east-central Asia and believed to have been introduced to the United States in the late 1800s, likely as hitchhikers in potted plants.
Unlike the common European nightcrawler, which gardeners generally welcome, the jumping worm degrades the very soil it inhabits.
“The jumping worms’ hyper-activity degrades the soil structure, can harm plant roots and accelerate soil drying,” the department said in its press release. “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.”
The worms are long, red-to-brown in color, can reach up to 6 inches in length and may appear metallic. When disturbed, they thrash erratically with a violent, snake-like motion — a behavior that gives them their various nicknames, including “crazy worm,” “snake worm” and “Georgia jumper.”
A telltale sign of infestation is soil with a distinctive granular, coffee-ground texture created by the worms’ castings. Unlike European nightcrawlers, which have a reddish band around the body, jumping worms have a distinct, smooth, white or cream-colored band called the clitellum.
The CDA is launching a public education campaign and is asking residents to take several precautions:
- Inspect soil, mulch and plants before purchasing or transplanting.
- Buy bare-root plants when possible.
- Do not share compost, mulch or soil from areas with known infestations.
- When purchasing bulk mulch or compost, confirm it has been heat-treated to at least 130 degrees for three days to kill cocoons.
- Clean soil from boots, tools and equipment before moving between sites.
Residents who suspect an infestation can report it through the CDA’s online jumping worm reporting form or visit the agency’s website for additional information.
