Jumping, 'Crazy' Worms Threaten Wisconsin Forests

Jun 25, 2015

The invasive 'jumping worm'
Credit UW Arboretum

A species of earthworms that is known to "act crazy, jump and thrash" is jumping and thrashing  its way across the state.

The worm goes by many names, including crazy worm, jumping worm and snake worm. It is officially known as the Amynthas agrestis and was identified at the UW Arboretum in Madison in October of 2013. Since then, it has turned up in multiple locations around the state, including Milwaukee.

According to a DNR fact sheet, the species originates in Asia and can "behave more like a threatened snake than a worm." The worms can get up to eight inches long.

The jumping worms have the potential to be as dangerous to Wisconsin’s forests as the Emerald Ash Borer and other invasive species.

"The biggest concern with this worm (as well as nightcrawlers) is that these earthworms consume the forest floor," Brad Herrick says. He is an ecologist and the research program manager at the UW-Madison Arboretum.

Herrick says that they have a voracious appetite. They eat the leaves off of the forest floor and can spread very quickly. "They will eat the leaf layer, which is a protective spongy layer that native plants need to germinate and to spread, and when that's gone it makes it very difficult for native plants to exist. We see a lot more soil erosion and...sets the stage for other invasive species - plants and animals - to move in," he adds.

Another big concern is that these worms reproduce without mating, or parthenogenically, which leads to rapid population growth. "They can really create high numbers quickly and move into the landscape faster," Herrick says.

To sum up the potential impact of these 'crazy, jumping worms,' Herrick says, "these worms can really fundamentally change the forest ecosystem."

So, what can you do to stop of the spread of the worms? Avoid areas where the worms have been spotted. If are you in an area where the worms exist, clean the bottom of your shoes after you leave the area. And, if you believe you have any of these worms on your property, email Bernie Williams, Wisconsin DNR, Invasive Plants and Earthworms Outreach Specialist.