Invasive Jumping Worms Spreading Across US, Including In NH

Find out about the "mustard test" for detecting the worms and how to control them if they are on your property.

By Joseph Hosey, Patch Staff

Apr 30, 2026 3:47 pm EDT

Asian jumping worms, an invasive, soil nutrient-gobbling earthworm that can leap a foot in the air, are moving rapidly across the country, with sightings in 38 states, including New Hampshire.

Asian jumping worms — their scientific name is Amynthas agrestis — have earned their nickname, and their reputation. They're also called Alabama jumpers, Jersey wrigglers, wood eel, crazy worms, snake worms, and crazy snake worms.

The Massachusetts Department of Agriculture and Resources provided a "mustard test" for detecting worms.

It consists of mixing one gallon of water with 1/3 cup of ground yellow mustard seed and then pouring slowly into soil that has been recently cleared of leaves, mulch, or compost. When worms come to the surface, check to see which ones match the jumping worm description, and that actually jump off the ground.

The Mass NRC said the "mustard test" will not harm soil or plants and can only be used for detecting — not controlling — the worms.

They have recently been spotted as far west as California and Colorado. According to data from EDDMapS, an online mapping service, other states reporting sightings include:

Northeast and Mid-Atlantic: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia and West Virginia.

Midwest: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, Ohio and Wisconsin.

South and Southeast: Alabama, Arkansas, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee

West and Mountain West: California, Colorado, Oregon and Washington.

The jumping worm’s common names are descriptive of “the way they thrash around,” USDA Forest Service soil scientist Mac Callaham said in a post on the agency’s website. “They can flip themselves a foot off the ground.”

Harmless earthworms aerate the soil and help prep it for growth, but once jumping worms have had their way in your dirt, it will have the consistency of coffee grounds and be about as useful for growing anything but frustration. Jumping worms also elbow other species out of the way, according to experts.

Jumping worm populations grow quickly through a couple of generations a season. Like other worms, they’re hermaphrodites, meaning they have both male and female reproductive organs, but with a distinction: Jumping worms reproduce on their own.

Jumping worms expend a lot of energy, which they fuel by eating everything in their path. That includes leaf litter, the first layer of soil on the forest floor, home not only to many unseen tiny creatures but also an important source of nutrients that plants need to sprout and grow.

Scientists say they need to learn more about the ecology of jumping worms before prescribing a management plan.

Jumping worms vary from red to brown in color. They can grow up to 6 inches in length, and their bodies may appear metallic. There's no way to completely eradicate them, experts say, but some steps to control their spread include:

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 degrees Fahrenheit for three days to kill the cocoons.
If you find them in your garden, seal them in a plastic bag and leave it in the sun for about 10 minutes before throwing it in the trash, or drown them in soapy water, vinegar or alcohol for about 20 minutes.